Break up /database-access/guides/

Closes #17641

Organize the guides to enrolling databases in specific cloud providers
(or self-hosted databases) into separate subsections of the "Database
Actions" section, organized by cloud provider (or self-hosted).

We can later add general information to the index page of each
subsection about how Teleport database access works for each cloud
provider. The remaining guides in the "Guides" subsection have to do
with database-agnostic functionality of the Teleport Database Service.

This change also adds a redirect for each page it moves.

docs/pages/database-access/enroll-aws-databases.mdx

@@ -0,0 +1,30 @@
+---
+title: Enroll AWS Databases
+description: "Provides instructions on protecting databases in your AWS-managed infrastructure with Teleport."
+---
+
+The guides in this section show you how to protect AWS-managed databases with
+Teleport.
+
+You can configure Teleport to discover databases in your AWS account and enroll
+them with your cluster automatically. Read more about [Teleport auto-discovery
+for AWS databases](./enroll-aws-databases/aws-discovery.mdx).
+
+It is also possible to protect databases across your AWS accounts. Read the
+instructions in [AWS Cross-Account Database
+Access](./enroll-aws-databases/aws-cross-account.mdx).
+
+Read the following guides for how to protect a specific AWS-managed database
+with Teleport:
+
+- [Amazon Redshift](./enroll-aws-databases/postgres-redshift.mdx)
+- [Amazon Redshift Serverless](./enroll-aws-databases/redshift-serverless.mdx)
+- [Amazon RDS](./enroll-aws-databases/rds.mdx)
+- [Amazon RDS for SQL Server](./enroll-aws-databases/sql-server-ad.mdx)
+- [Amazon RDS Proxy for PostgreSQL](./enroll-aws-databases/rds-proxy-postgres.mdx)
+- [Amazon RDS Proxy for Microsoft SQL Server](./enroll-aws-databases/rds-proxy-sqlserver.mdx)
+- [Amazon RDS Proxy MySQL](./enroll-aws-databases/rds-proxy-mysql.mdx)
+- [Amazon OpenSearch](./enroll-aws-databases/aws-opensearch.mdx)
+- [Amazon DynamoDB](./enroll-aws-databases/aws-dynamodb.mdx)
+- [AWS Keyspaces (Apache Cassandra)](./enroll-aws-databases/aws-cassandra-keyspaces.mdx)
+- [AWS ElastiCache and AWS MemoryDB for Redis](./enroll-aws-databases/redis-aws.mdx)

docs/pages/database-access/enroll-azure-databases.mdx

@@ -0,0 +1,11 @@
+---
+title: Enroll Azure Databases
+description: "Provides instructions on protecting databases in your Azure-managed infrastructure with Teleport."
+---
+
+You can protect Azure-managed databases with Teleport. Learn how to enroll the
+following databases:
+
+- [Azure SQl Server](./enroll-azure-databases/azure-sql-server-ad.mdx)
+- [Azure Database for PostgreSQL or MySQL Server](./enroll-azure-databases/azure-postgres-mysql.mdx)
+- [Azure Redis](./enroll-azure-databases/azure-redis.mdx)

docs/pages/database-access/enroll-google-cloud-databases.mdx

@@ -0,0 +1,10 @@
+---
+title: Enroll Google Cloud Databases
+description: "Provides instructions on protecting databases in your Google Cloud-managed infrastructure with Teleport."
+---
+
+You can protect databases hosted on Google Cloud with Teleport. Read the
+following guides for instructions on enrolling a specific database:
+
+- [PostgreSQL on Google Cloud SQL](./enroll-google-cloud-databases/postgres-cloudsql.mdx)
+- [MySQL on Google Cloud SQL](./enroll-google-cloud-databases/mysql-cloudsql.mdx)

docs/pages/database-access/enroll-managed-databases.mdx

@@ -0,0 +1,10 @@
+---
+title: Enroll Cloud-Hosted Database Platforms
+description: "Provides instructions on protecting managed databases in your infrastructure with Teleport."
+---
+
+Teleport can protect databases that are managed as a dedicated cloud platform.
+Learn how to enroll the following databases in your Teleport cluster:
+
+- [MongoDB Atlas](./enroll-managed-databases/mongodb-atlas.mdx)
+- [Snowflake](./enroll-managed-databases/snowflake.mdx)

docs/pages/database-access/enroll-self-hosted-databases.mdx

@@ -0,0 +1,22 @@
+---
+title: Enroll Self-Hosted Databases
+description: "Provides instructions on protecting self-hosted databases in your infrastructure with Teleport."
+---
+
+You can protect self-hosted databases with Teleport. Learn how to enroll your
+database in your Teleport cluster with the following guides:
+
+- [Cassandra and
+  ScyllaDB](./enroll-self-hosted-databases/cassandra-self-hosted.mdx)
+- [ClickHouse](./enroll-self-hosted-databases/clickhouse-self-hosted.mdx)
+- [CockroachDB](./enroll-self-hosted-databases/cockroachdb-self-hosted.mdx)
+- [Elastic](./enroll-self-hosted-databases/elastic.mdx)
+- [MongoDB](./enroll-self-hosted-databases/mongodb-self-hosted.mdx)
+- [MySQL](./enroll-self-hosted-databases/mysql-self-hosted.mdx)
+- [Oracle](./enroll-self-hosted-databases/oracle-self-hosted.mdx)
+- [PostgreSQL](./enroll-self-hosted-databases/postgres-self-hosted.mdx)
+- [Redis Cluster](./enroll-self-hosted-databases/redis-cluster.mdx)
+- [Redis](./enroll-self-hosted-databases/redis.mdx)
+- [SQL Server with PKINIT
+  authentication](./enroll-self-hosted-databases/sql-server-ad-pkinit.mdx)
+- [Vitess](./enroll-self-hosted-databases/vitess.mdx)

docs/pages/database-access/guides.mdx

@@ -4,4 +4,17 @@ description: Guides for configuring Teleport database access with self-hosted or
 layout: tocless-doc
 ---
 
-(!docs/pages/includes/database-access/guides.mdx!)
+The Teleport Database Service proxies connections to databases protected by
+Teleport. Read more about deploying the Teleport Database Service and
+enrolling databases:
+
+- [High Availability](./database-access/guides/ha.mdx): Learn how to deploy
+  multiple instances of the Teleport Database Service to proxy the same set of
+  databases.
+- [Dynamic Registration](./guides/dynamic-registration.mdx): Learn how to enroll
+  databases without re-deploying the Teleport Database Service.
+
+The Teleport Database Service is one service that you can run on an a Teleport
+**agent.** Read the [Teleport Agents](../../agents/introduction.mdx)
+documentation for all of the methods you can use to join agents to your cluster
+in order to proxy various kinds of infrastructure resources.

docs/pages/database-access/introduction.mdx

@@ -39,14 +39,38 @@ with GitHub, execute a few SQL queries and observe them in the audit log:
   Your browser does not support the video tag.
 </video>
 
-## Getting started
+## Get started
 
 - [Getting started](./getting-started.mdx): Connect Aurora PostgreSQL in a 10
   minute guide.
 
-(!docs/pages/includes/database-access/guides.mdx!)
+## Connect your database
 
-## Resources
+Teleport can protect both self-hosted and managed databases. Learn how to set up
+secure access to databases in your infrastructure:
+
+- Managed [Amazon Web Services](./enroll-aws-databases.mdx) databases
+- Managed [Google Cloud](./enroll-google-cloud-databases.mdx) databases
+- [Self-Hosted](./enroll-self-hosted-databases.mdx) databases, regardless of
+  cloud provider
+- Managed [Microsoft Azure](./enroll-azure-databases.mdx) databases
+- [Database-specific cloud
+  platforms](docs/pages/database-access//enroll-managed-databases.mdx) such as
+  Snowflake and MongoDB Atlas
+
+## Manage the Teleport Database Service
+
+The Teleport Database Service proxies connections to databases protected by
+Teleport. Read more about deploying the Teleport Database Service and
+enrolling databases:
+
+- [High Availability](./database-access/guides/ha.mdx): Learn how to deploy
+  multiple instances of the Teleport Database Service to proxy the same set of
+  databases.
+- [Dynamic Registration](./guides/dynamic-registration.mdx): Learn how to enroll
+  databases without re-deploying the Teleport Database Service.
+
+## Learn more
 
 To learn more about configuring role-based access control for database access,
 check out the [RBAC](./rbac.mdx) section.