Configure CI for lab1

.github/workflows/testlab1.yml

@@ -0,0 +1,23 @@
+name: lab1 - test & lint
+
+on:
+  push:
+    paths:
+      - 'lab1/**'
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: erlef/setup-beam@v1
+        with:
+          otp-version: "28"
+          gleam-version: "1.13.0"
+          rebar3-version: "3"
+          # elixir-version: "1"
+      - run cd lab1
+      - run: gleam deps download
+      - run: gleam test
+      - run: gleam format --check src test