📝 improve github enterprise docs (#244)

Author: yanyongyu

docs/quickstart/connecting-to-github-enterprise.md

@@ -1,38 +1,46 @@
 # Connecting to GitHub Enterprise
 
-Connecting to the GitHub Enterprise is similar to the public GitHub API, but requires two specific configurations:
+Connecting to GitHub Enterprise is similar to using the public GitHub API, but requires two specific configurations. Each is explained below with brief guidance and examples.
 
-- To connect to **GitHub Enterprise Server**, you must provide the server's API endpoint in the `base_url` parameter.
-- You need to switch the REST API schema version when using client.
+## Provide the server API endpoint
 
-=== "Sync"
+When connecting to a GitHub Enterprise Server (GHES or GHEC), you must set the server's REST API endpoint via the `base_url` parameter when creating the client. Use the full API base URL for your instance (for example `https://example.ghe.com/api/v3/`). githubkit will ensure the trailing slash is present.
+
+This tells the client where to send REST and GraphQL requests rather than the public GitHub endpoints.
+
+```python hl_lines="4 7"
+from githubkit import GitHub
+from githubkit.versions.latest.models import PublicUser, PrivateUser
+
+github = GitHub("<your_token_here>", base_url="https://example.ghe.com/api/v3/")
+```
+
+## Switch the REST API schema version
 
-    ```python hl_lines="4 7"
-    from githubkit import GitHub
-    from githubkit.versions.latest.models import PublicUser, PrivateUser
+GitHub Enterprise Server may require a different REST API schema/version than the public API. Use the `rest("<schema-version>")` selector on the client to choose the correct REST schema for your server (for example `ghec-2022-11-28`). Picking the right schema ensures endpoint signatures match your server version and provides autocompletion support in your IDE.
 
-    github = GitHub("<your_token_here>", base_url="https://example.ghe.com/api/v3/")
+The examples below demonstrate how to use both REST API and GraphQL API calls:
 
-    # call GitHub rest api
+=== "Sync"
+
+    ```python hl_lines="2"
+    # Call the GitHub REST API with a specific schema version
     resp = github.rest("ghec-2022-11-28").users.get_authenticated()
     user: PublicUser | PrivateUser = resp.parsed_data
 
-    # call GitHub graphql api
+    # Call the GitHub GraphQL API
     data: dict = github.graphql("{ viewer { login } }")
     ```
 
 === "Async"
 
-    ```python hl_lines="4 7"
-    from githubkit import GitHub
-    from githubkit.versions.latest.models import PublicUser, PrivateUser
-
-    github = GitHub("<your_token_here>", base_url="https://example.ghe.com/api/v3/")
-
-    # call GitHub rest api
+    ```python hl_lines="2"
+    # Call the GitHub REST API with a specific schema version
     resp = await github.rest("ghec-2022-11-28").users.async_get_authenticated()
     user: PublicUser | PrivateUser = resp.parsed_data
 
-    # call GitHub graphql api
+    # Call the GitHub GraphQL API
     data: dict = await github.async_graphql("{ viewer { login } }")
     ```
+
+For more information, see [REST API Versioning](../usage/rest-api.md#rest-api-versioning).