Rename "Installer API" to "Legacy Installer API" and update related documentation; remove obsolete API files.

Author: DerGoogler

docs/.vitepress/config/en.ts

@@ -98,7 +98,7 @@ function sidebarGuide() {
         { text: "How a Module Card Works", link: "/guide/how-a-module-card-works" },
         { text: "Anti-Features", link: "/guide/antifeatures" },
         { text: "Text Formatting", link: "/guide/text-formatting" },
-        { text: "Installer API", link: "/guide/installer" },
+        { text: "Legacy Installer API", link: "/guide/installer" },
         { text: "FAQ", link: "/guide/faq" },
       ],
     },

docs/en/guide/installer.md

@@ -1,4 +1,8 @@
-# Installer API
+# Legacy Installer API
+
+> [!WARNING]
+> This API has been removed in **MMRL** *v33870*.   
+> Please use the **Installer V2 API** instead.
 
 You can control some parts of the terminal. The API is listed below