Degit in Github

Generate a button and add a shortcut key to fast copy a Degit command path in github repository page [v0.0.3 changelog](https://github.com/aliuq/degit-webext/releases/tag/v0.0.3) e.g. `https://github.com/vuejs/core/tree/main/scripts` -> `npx degit vuejs/core/scripts#main`