CI: Support automatic publish to crates.io on tag creation

This would make it easier to release new crate, without having to
ping anyone.

Whoever has the right to create a new release on GitHub shall have the right
to publish it to crates.io

Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>

.github/workflows/publish.yml

@@ -0,0 +1,15 @@
+on:
+  push:
+    tags:
+      - "*"
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Publish to crates.io
+        run: |
+          cargo publish
+        env:
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}