Eslint - require copyright header rule (#8514)

* bump eslint plugin to 0.5.2

Signed-off-by: Kerry Archibald <kerrya@element.io>

* add rule

Signed-off-by: Kerry Archibald <kerrya@element.io>

* add missing copyright headers

Signed-off-by: Kerry Archibald <kerrya@element.io>

* fix comment order

Signed-off-by: Kerry Archibald <kerrya@element.io>

package.json

@@ -173,7 +173,7 @@
     "eslint-config-google": "^0.14.0",
     "eslint-plugin-import": "^2.25.4",
     "eslint-plugin-jsx-a11y": "^6.5.1",
-    "eslint-plugin-matrix-org": "^0.4.0",
+    "eslint-plugin-matrix-org": "^0.5.2",
     "eslint-plugin-react": "^7.28.0",
     "eslint-plugin-react-hooks": "^4.3.0",
     "fs-extra": "^10.0.1",