Add GitHub action to check ReST input files

Author: RKrahl

.github/workflows/rst-lint.yaml

@@ -0,0 +1,12 @@
+name: Check ReST input files
+on: [push, pull_request]
+jobs:
+  doc8:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v4
+      - name: doc8-check
+        uses: deep-entertainment/doc8-action@v4
+        with:
+          scan-paths: "/doc/src, README.rst, CHANGES.rst"