add GitHub Actions main.yml

Author: wilgert

.github/workflows/main.yml

@@ -0,0 +1,18 @@
+name: CheckHomework
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Run a one-line script
+        run: echo Hello, world!
+      - name: Current Branch
+        uses: ryolambert/current-branch@v1.0
+      - name: Run a multi-line script
+        run: |
+          echo Add other actions to build,
+          echo test, and deploy your project.