ci: automatically create github releases on tags

Author: figsoda

.github/workflows/release.yml

@@ -0,0 +1,14 @@
+name: release
+
+on:
+  push:
+    tags:
+      - v[0-9]+.[0-9]+.[0-9]+
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: softprops/action-gh-release@v1
+        with:
+          body: "[CHANGELOG.md](https://github.com/nix-community/nix-init/blob/main/CHANGELOG.md)"