feat(nix): allow the user to specify the package being used

.github/workflows/rustfmt.yml

@@ -0,0 +1,17 @@
+name: "rustfmt"
+on:
+  push:
+  pull_request:
+
+jobs:
+  formatting:
+    name: cargo fmt
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      # Ensure rustfmt is installed and setup problem matcher
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          components: rustfmt
+      - name: Rustfmt Check
+        uses: actions-rust-lang/rustfmt@v1

CHANGELOG.md

@@ -6,6 +6,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- add `set_alpha` filter
+
+
 ## [2.3.0](https://github.com/InioX/matugen/compare/v2.2.0...v2.3.0) - 2024-05-29
 
 ### Added