docs: Update rust-analyzer docs (#17988)

Release Notes:

- N/A

docs/src/languages/rust.md

@@ -13,37 +13,29 @@ TBD: Provide explicit examples not just `....`
 
 ## Inlay Hints
 
-The following configuration can be used to enable inlay hints for rust:
+The following configuration can be used to change the inlay hint settings for `rust-analyzer` in Rust:
 
 ```json
+{
+  "lsp": {
+    "rust-analyzer": {
+      "initialization_options": {
         "inlayHints": {
           "maxLength": null,
           "lifetimeElisionHints": {
-  "useParameterNames": true,
             "enable": "skip_trivial"
+            "useParameterNames": true,
           },
           "closureReturnTypeHints": {
             "enable": "always"
           }
         }
-```
-
-to make the language server send back inlay hints when Zed has them enabled in the settings.
-
-Use
-
-```json
-"lsp": {
-  "rust-analyzer": {
-    "initialization_options": {
-      ....
+      }
     }
   }
 }
 ```
 
-to override these settings.
-
 See [Inlay Hints](https://rust-analyzer.github.io/manual.html#inlay-hints) in the Rust Analyzer Manual for more information.
 
 ## Target directory
@@ -70,7 +62,23 @@ A `true` setting will set the target directory to `target/rust-analyzer`. You ca
 
 You can configure which `rust-analyzer` binary Zed should use.
 
-To use a binary in a custom location, add the following to your `settings.json`:
+By default, Zed will try to find a `rust-analyzer` in your `$PATH` and try to use that. If that binary successfully executes `rust-analyzer --help`, it's used. Otherwise, Zed will fall back to installing its own `rust-analyzer` version and using that.
+
+If you want to disable Zed looking for a `rust-analyzer` binary, you can set `path_lookup` to `false` in your `settings.json`:
+
+```json
+{
+  "lsp": {
+    "rust-analyzer": {
+      "binary": {
+        "path_lookup": false
+      }
+    }
+  }
+}
+```
+
+If you want to use a binary in a custom location, you can specify a `path` and optional `args`:
 
 ```json
 {
@@ -85,19 +93,7 @@ To use a binary in a custom location, add the following to your `settings.json`:
 }
 ```
 
-To use a binary that is on your `$PATH`, add the following to your `settings.json`:
-
-```json
-{
-  "lsp": {
-    "rust-analyzer": {
-      "binary": {
-        "path_lookup": true
-      }
-    }
-  }
-}
-```
+This `"path"` has to be an absolute path.
 
 ## More server configuration
 
@@ -138,7 +134,8 @@ Check on save feature is responsible for returning part of the diagnostics based
 Consider more `rust-analyzer.cargo.` and `rust-analyzer.check.` and `rust-analyzer.diagnostics.` settings from the manual for more fine-grained configuration.
 Here's a snippet for Zed settings.json (the language server will restart automatically after the `lsp.rust-analyzer` section is edited and saved):
 
-```json5
+```json
+{
   "lsp": {
     "rust-analyzer": {
       "initialization_options": {
@@ -163,6 +160,7 @@ Here's a snippet for Zed settings.json (the language server will restart automat
       }
     }
   }
+}
 ```
 
 ### Snippets
@@ -170,6 +168,7 @@ Here's a snippet for Zed settings.json (the language server will restart automat
 There's a way get custom completion items from rust-analyzer, that will transform the code according to the snippet body:
 
 ```json
+{
   "lsp": {
     "rust-analyzer": {
       "initialization_options": {
@@ -216,4 +215,5 @@ There's a way get custom completion items from rust-analyzer, that will transfor
       }
     }
   }
+}
 ```