Fix documentation issues and add CHANGELOG entry

1. Fix broken link in configuration-deprecated.md
   - Changed from non-existent release-notes path to CHANGELOG.md

2. Improve generator template clarity
   - Added 'Two mutually exclusive approaches' heading
   - Makes it clearer that users should choose ONE approach

3. Add CHANGELOG entry for documentation improvements
   - Documents configuration simplification
   - Documents new testing guide
   - Documents Doctor enhancements

Addresses reviewer feedback on documentation quality.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

CHANGELOG.md

@@ -55,6 +55,10 @@ Changes since the last non-beta release.
 
 - **`generated_component_packs_loading_strategy` now defaults based on Pro license**: When using Shakapacker >= 8.2.0, the default loading strategy is now `:async` for Pro users and `:defer` for non-Pro users. This provides optimal performance for Pro users while maintaining compatibility for non-Pro users. You can still explicitly set the strategy in your configuration. [PR #1993](https://github.com/shakacode/react_on_rails/pull/1993) by [AbanoubGhadban](https://github.com/AbanoubGhadban).
 
+#### Documentation
+
+- **Simplified Configuration Files**: Improved configuration documentation and generator template for better clarity and usability. Reduced generator template from 67 to 42 lines (37% reduction). Added comprehensive testing configuration guide. Reorganized configuration docs into Essential vs Advanced sections. Enhanced Doctor program with diagnostics for server rendering and test compilation consistency. [PR 2011](https://github.com/shakacode/react_on_rails/pull/2011) by [justin808](https://github.com/justin808).
+
 #### Bug Fixes
 
 - **Use as Git dependency**: All packages can now be installed as Git dependencies. This is useful for development and testing purposes. See [CONTRIBUTING.md](./CONTRIBUTING.md#git-dependencies) for documentation. [PR #1873](https://github.com/shakacode/react_on_rails/pull/1873) by [alexeyr-ci2](https://github.com/alexeyr-ci2).

docs/api-reference/configuration-deprecated.md

@@ -43,7 +43,7 @@ config.defer_generated_component_packs = true
 config.generated_component_packs_loading_strategy = :defer
 ```
 
-See the [16.0.0 Release Notes](../upgrading/release-notes/16.0.0.md) for more details.
+See [CHANGELOG.md](../../CHANGELOG.md) for more details.
 
 ## Need Help?
 

lib/generators/react_on_rails/templates/base/base/config/initializers/react_on_rails.rb.tt

@@ -13,8 +13,10 @@ ReactOnRails.configure do |config|
   config.server_bundle_js_file = "server-bundle.js"
 
   ################################################################################
-  # Test Configuration (Optional - see below)
+  # Test Configuration (Optional)
   ################################################################################
+  # Two mutually exclusive approaches - use ONE of the following:
+  #
   # RECOMMENDED: Set `compile: true` in config/shakapacker.yml for test environment
   # This is simpler and handled automatically by Shakapacker.
   #