Full rewrite

.github/workflows/shellcheck.yml

@@ -0,0 +1,17 @@
+name: Shellcheck CI
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  shellcheck:
+    runs-on: ubuntu-latest
+    if: "! contains(toJSON(github.event.commits.*.message), '[skip ci]')"
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Check for code quality errors
+      run: ./run_linter.sh