Configure scheduled weekly build (#340)

Signed-off-by: Mark S. Lewis <Mark.S.Lewis@outlook.com>

Author: bestbeforetoday

.github/workflows/schedule.yml

@@ -0,0 +1,10 @@
+name: Scheduled build
+
+on:
+  schedule:
+    - cron: "5 4 * * 0"
+  workflow_dispatch:
+
+jobs:
+  main:
+    uses: ./.github/workflows/test.yml