docs(readme): fix release badge

README.md

@@ -125,7 +125,7 @@ Override it by defining buffer local `b:fennel_use_lume`.
 [script-badge]: https://img.shields.io/badge/Made%20with%20Vimscript-019733.svg?logo=vim&style=flat-square
 [ci-badge]: https://img.shields.io/github/actions/workflow/status/mnacamura/vim-fennel-syntax/ci.yml?logo=github&label=CI&style=flat-square
 [ci-jobs]: https://github.com/mnacamura/vim-fennel-syntax/actions/workflows/ci.yml
-[release-badge]: https://img.shields.io/github/release/mnacamura/vim-fennel-syntax.svg&style=flat-square
+[release-badge]: https://img.shields.io/github/release/mnacamura/vim-fennel-syntax.svg?style=flat-square
 [release-list]: https://github.com/mnacamura/vim-fennel-syntax/releases
 [fennel-badge]: https://img.shields.io/badge/Fennel-v1.4.0-fff3d7.svg?style=flat-square
 [fennel-homepage]: https://fennel-lang.org/