Update setting description to match reality (#10600)

Author: t3chguy

src/i18n/strings/en_EN.json

@@ -1017,7 +1017,7 @@
     "Surround selected text when typing special characters": "Surround selected text when typing special characters",
     "Automatically replace plain text Emoji": "Automatically replace plain text Emoji",
     "Enable Markdown": "Enable Markdown",
-    "Start messages with <code>/plain</code> to send without markdown and <code>/md</code> to send with.": "Start messages with <code>/plain</code> to send without markdown and <code>/md</code> to send with.",
+    "Start messages with <code>/plain</code> to send without markdown.": "Start messages with <code>/plain</code> to send without markdown.",
     "Mirror local video feed": "Mirror local video feed",
     "Match system theme": "Match system theme",
     "Use a system font": "Use a system font",

src/settings/Settings.tsx

@@ -683,7 +683,7 @@ export const SETTINGS: { [setting: string]: ISetting } = {
         displayName: _td("Enable Markdown"),
         description: () =>
             _t(
-                "Start messages with <code>/plain</code> to send without markdown and <code>/md</code> to send with.",
+                "Start messages with <code>/plain</code> to send without markdown.",
                 {},
                 { code: (sub) => <code>{sub}</code> },
             ),