docs: Improve Markdown trailing whitespace section (#19630)

docs/src/languages/markdown.md

@@ -21,13 +21,26 @@ def fib(n):
 
 ## Configuration
 
-If you wish change the default language settings for Markdown files, perhaps to disable auto format on save or if your markdown relies upon trailing whitespace `  ` being converted to `<br />` you can add change these values in your `settings.json`:
+### Format
+
+Zed supports using Prettier to automatically re-format Markdown documents. You can trigger this manually via the {#action editor::Format} action or via the {#kb editor::Format} keyboard shortcut. Alternately, you can automattically format by enabling [`format_on_save`](./configuring-zed.md#format-on-save) in your settings.json:
 
 ```json
   "languages": {
     "Markdown": {
-      "remove_trailing_whitespace_on_save": true,
       "format_on_save": "on"
     }
   },
 ```
+
+### Trailing Whitespace
+
+By default Zed will remove trailing whitespace on save. If you rely on invisible trailing whitespace being converted to `<br />` in Markdown files you can disable this behavior with:
+
+```json
+  "languages": {
+    "Markdown": {
+      "remove_trailing_whitespace_on_save": false
+    }
+  },
+```