readme: add support matrix

.github/workflows/ci.yaml

@@ -0,0 +1,40 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+  workflow_dispatch:
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        zig-version: ["0.13.0"]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        include:
+          - zig-version: "0.12.1"
+            os: ubuntu-latest
+          - zig-version: "master"
+            check-format: true
+            os: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Zig
+        uses: mlugg/setup-zig@v1
+        with:
+          version: ${{ matrix.zig-version }}
+
+      - if: ${{ matrix.check-format }}
+        name: Check Formatting
+        run: zig fmt --ast-check --check .
+
+      - name: Build
+        run: zig build --summary all

readme.md

@@ -28,3 +28,9 @@ const protobuf_c_dep = b.dependency("protobuf_c", .{
 });
 your_exe.linkLibrary(protobuf_c_dep.artifact("protobuf_c"));
 ```
+
+## Version Support Matrix
+
+|  Refname | protobuf-c Version | Zig `0.12.x` | Zig `0.13.x` | Zig `0.14.0-dev` |
+|----------|--------------------|--------------|--------------|------------------|
+| `1.5.0`  | `1.5.0`            | ✅           | ✅          | ✅              |