update README

README.md

@@ -1,2 +1,50 @@
-# superset_client
-Superset Client
+# Superset Client
+
+A Ruby client for interacting with Apache Superset's REST API.
+
+## Installation
+
+Add this line to your application's Gemfile:
+
+```ruby
+gem 'superset_client'
+```
+
+And then execute:
+
+    $ bundle install
+
+Or install it yourself as:
+
+    $ gem install superset_client
+
+## Usage
+
+```ruby
+# Create a new client
+client = SupersetClient.new('https://your-superset-instance', 'username', 'password')
+
+# Or if you prefer the explicit form
+client = SupersetClient::Client.new('https://your-superset-instance', 'username', 'password')
+
+# Get all charts
+charts = client.charts
+
+# Get a specific chart
+chart = client.chart(123)
+
+# Create a new chart
+new_chart = client.create_chart({
+  slice_name: "My New Chart",
+  viz_type: "line",
+  # ... other params
+})
+```
+
+## Development
+
+After checking out the repo, run `nix-shell` to install dependencies. Then, run `bundle exec spec` to run the tests.
+
+## License
+
+The gem is available as open source under the terms of the MIT License.