add copyright headers

res/themes/light-custom/css/_custom.scss

@@ -1,3 +1,19 @@
+/*
+Copyright 2019 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 //
 // --accent-color
 $accent-color: var(--accent-color);

src/theme.js

@@ -1,5 +1,6 @@
 /*
 Copyright 2019 Michael Telatynski <7t3chguy@gmail.com>
+Copyright 2019 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.