Document new indexing configuration approach (#2319)

Author: andyw8

EDITORS.md

@@ -205,3 +205,19 @@ You can use the Ruby LSP with RubyMine (or IntelliJ IDEA Ultimate) through the f
 Note that there might be overlapping functionality when using it with RubyMine, given that the IDE provides similar features as the ones coming from the Ruby LSP.
 
 [Ruby LSP plugin](https://plugins.jetbrains.com/plugin/24413-ruby-lsp)
+
+# Indexing Configuration
+
+To configure indexing, pass a JSON hash as part of the initialization options for your editor, for example:
+
+```json
+{
+  "indexing": {
+    "excludedPatterns": ["**/test/**.rb"],
+    "includedPatterns": ["**/bin/**"],
+    "excludedGems": ["rubocop", "rubocop-performance"],
+    "includedPatterns": ["rake"],
+    "excludedMagicComments": ["compiled:true"]
+  }
+}
+```

README.md

@@ -78,7 +78,12 @@ default gems, except for
 - Gems that only appear under the `:development` group
 - All Ruby files under `test/**/*.rb`
 
-By creating a `.index.yml` file, these configurations can be overridden and tuned. Note that indexing dependent behavior, such as definition, hover, completion or workspace symbol will be impacted by the configurations placed here.
+This behaviour can be overridden and tuned. Learn how to configure it [for VS Code](vscode/README.md#Indexing-Configuration) or [for other editors](EDITORS.md#Indexing-Configuration).
+
+Note that indexing-dependent behavior, such as definition, hover, completion or workspace symbol will be impacted by
+the configuration changes.
+
+The older approach of using a `.index.yml` file has been deprecated and will be removed in a future release.
 
 ```yaml
 # Exclude files based on a given pattern. Often used to exclude test files or fixtures

lsp.code-workspace

@@ -18,9 +18,11 @@
             "**/out": true,
         },
         "rubyLsp.bypassTypechecker": true,
-        "rubyLsp.excludedPatterns": [
-            "**/test/fixtures/**/*.rb"
-        ],
+        "rubyLsp.indexing": {
+            "excludedPatterns": [
+                "**/test/fixtures/**/*.rb"
+            ],
+        },
         "typescript.tsc.autoDetect": "off",
     }
 }

vscode/README.md

@@ -440,3 +440,20 @@ When `rubyLsp.formatter` is set to `auto`, Ruby LSP tries to determine which for
 If the bundle has a **direct** dependency on a supported formatter, such as `rubocop` or `syntax_tree`, that will be used.
 Otherwise, formatting will be disabled and you will need add one to the bundle. Using globally installed formatters or
 linters is not supported, they must in your Gemfile or gemspec.
+
+## Indexing Configuration
+
+To configure indexing, pass a JSON hash as part of the Ruby LSP configuration, for example:
+
+```jsonc
+// PROJECT/.vscode/settings.json
+{
+  "rubyLsp.indexing": {
+    "excludedPatterns": ["**/test/**.rb"],
+    "includedPatterns": ["**/bin/**"],
+    "excludedGems": ["rubocop", "rubocop-performance"],
+    "includedPatterns": ["rake"],
+    "excludedMagicComments": ["compiled:true"],
+  },
+}
+```