Add draft of build action

.forgejo/workflows/build.yaml

@@ -0,0 +1,21 @@
+---
+on: [push]
+
+name: Build
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Check out the code
+        uses: action/checkout@v4
+      - name: Set up the build environment
+        run: cmake .
+      - name: Compile the code
+        run: cmake --build .
+      - name: Save executable
+        uses: forgejo/upload-artifact@v4
+        with:
+          name: bin.zip
+          path: perlin-noise