Add build workflow

Closes #7

.github/workflows/build.yml

@@ -0,0 +1,28 @@
+name: "Stoney kernel"
+on:
+  push:
+    branches: [ "main" ]
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Maximize build space
+        uses: easimon/maximize-build-space@master
+        with:
+          root-reserve-mb: 5120
+          swap-size-mb: 1024
+          remove-dotnet: 'true'
+      - name: Check out
+        uses: actions/checkout@v3
+      - name: Install dependencies
+        run: sudo apt update; sudo apt install -y git build-essential ncurses-dev xz-utils libssl-dev bc flex libelf-dev bison binutils
+      - name: Build kernel
+        run: bash build.sh
+      - name: Upload build artifacts
+        uses: actions/upload-artifact@v3
+        with:
+          name: stoney-kernel
+          path: |
+            build/kernel.tar.gz