readme: added information about lint (#90)

README.md

@@ -153,7 +153,21 @@ All inputs are optional as they may be specified in the Atlas configuration file
 
 ### `ariga/atlas-action/migrate/lint`
 
-TODO
+Lint migration changes with Atlas
+
+#### Inputs
+
+All inputs are optional as they may be specified in the Atlas configuration file.
+
+* `dir` - The URL of the migration directory to lint.  For example: `file://migrations`.
+  Read more about [Atlas URLs](https://atlasgo.io/concepts/url).
+* `dir-name` - The name of the project in Atlas Cloud.
+* `dev-url` - The URL of the dev-database to use for analysis.  For example: `mysql://root:pass@localhost:3306/dev`.
+  Read more about [dev-databases](https://atlasgo.io/concepts/dev-database).description: The migration directory URL (i.e file://path/to/migrations)
+* `config` The path to the Atlas configuration file.  By default, Atlas will look for a file
+  named `atlas.hcl` in the current directory. For example, `file://config/atlas.hcl`.
+  Learn more about [Atlas configuration files](https://atlasgo.io/atlas-schema/projects).
+* `env` The environment to use from the Atlas configuration file.  For example, `dev`.
 
 ### `ariga/atlas-action/migrate/apply`