add spacing variables (#7456)

* add spacing variables

Signed-off-by: Kerry Archibald <[email protected]>

* eof

Signed-off-by: Kerry Archibald <[email protected]>

Author: Kerry

res/css/_components.scss

@@ -3,6 +3,7 @@
 @import "./_common.scss";
 @import "./_font-sizes.scss";
 @import "./_font-weights.scss";
+@import "./_spacing.scss";
 @import "./structures/_AutoHideScrollbar.scss";
 @import "./structures/_BackdropPanel.scss";
 @import "./structures/_CompatibilityPage.scss";

res/css/_spacing.scss

@@ -0,0 +1,27 @@
+/*
+Copyright 2022 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.
+*/
+
+// 1rem :: 10px
+
+$spacing-4: 4px;
+$spacing-8: 8px;
+$spacing-12: 12px;
+$spacing-16: 16px;
+$spacing-20: 20px;
+$spacing-24: 24px;
+$spacing-28: 28px;
+$spacing-32: 32px;
+$spacing-40: 40px;