CI: workflow tes (push/PR) + rilis otomatis dari tag

- .github/workflows/ci.yml: vet + go test -race di ubuntu-22.04
- .github/workflows/release.yml: tag vX.Y.Z -> tes, build AppImage dengan versi
  dari tag, lalu gh release create dengan aset AppImage + zsync dan catatan
  rilis otomatis (--generate-notes)
- README: rilis cukup 'git tag v1.1.0 && git push --tags'

.github/workflows/ci.yml

@@ -0,0 +1,31 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  test:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+
+      # Fyne butuh header X11/OpenGL dan cgo untuk dikompilasi.
+      - name: Install build dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends \
+            libgl1-mesa-dev libx11-dev xorg-dev libxkbcommon-dev libwayland-dev
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+
+      - name: Vet
+        run: go vet ./...
+
+      - name: Test
+        run: go test -race ./...