[GL2GH] Convert GitLab CI to GitHub Actions

Far simple than what we did in KPA.

Fixes: #41

.github/workflows/main.yml

@@ -0,0 +1,20 @@
+name: Check markdown quality via Linter
+
+env:
+  KPA_PROJECT: kiratech
+
+on: [push]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    container:
+      image: ghcr.io/mmul-it/kpa:v1.0.0
+      options: --user root
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+      - name: Create symlink to workspace
+        run: ln -sf /__w/labs/labs /kpa/projects/${KPA_PROJECT}
+      - name: Check markdown files for example project
+        run: mdl -c /kpa/.mdlrc $(find /kpa/projects/${KPA_PROJECT} -name '*.md')