feat: messages extension (#4028)

* feat: private messages

extensions/messages/js/tsconfig.json

@@ -0,0 +1,15 @@
+{
+    // Use Flarum's tsconfig as a starting point
+    "extends": "flarum-tsconfig",
+    // This will match all .ts, .tsx, .d.ts, .js, .jsx files in your `src` folder
+    // and also tells your Typescript server to read core's global typings for
+    // access to `dayjs` and `$` in the global namespace.
+    "include": ["src/**/*", "../../../framework/core/js/dist-typings/@types/**/*", "@types/**/*"],
+    "compilerOptions": {
+        // This will output typings to `dist-typings`
+        "declarationDir": "./dist-typings",
+        "paths": {
+            "flarum/*": ["../../../framework/core/js/dist-typings/*"]
+        }
+    }
+}