Add eslint rule to forbid vanilla imports in glitch (#2293)

Signed-off-by: Plastikmensch <plastikmensch@users.noreply.github.com>

.eslintrc.js

@@ -261,6 +261,18 @@ module.exports = {
       },
     ],
 
+    // Forbid imports from vanilla in glitch flavour
+    'import/no-restricted-paths': [
+      'error',
+      {
+        zones: [{
+          target: 'app/javascript/flavours/glitch/',
+          from: 'app/javascript/mastodon/',
+          message: 'Import from /flavours/glitch/ instead'
+        }]
+      }
+    ],
+
     'promise/always-return': 'off',
     'promise/catch-or-return': [
       'error',