Add Alpine Linux install docs

ajhalili2006 · web-flow · commit 354bac82b3a5 · 2021-12-24T18:43:22.000+08:00
diff --git a/docs/install_linux.md b/docs/install_linux.md
@@ -179,6 +179,23 @@ openSUSE Tumbleweed users can install from the [official distribution repo](http
 sudo zypper in gh
 ```
 
+### Alpine Linux
+
+Alpine Linux users can install from the [stable releases' community packaage repository](https://pkgs.alpinelinux.org/packages?name=github-cli&branch=v3.15).
+
+```bash
+apk add github-cli
+```
+
+Users wanting the latest version of the CLI without waiting to be backported into their stable release they're using should use the edge release's
+community repo through this method below, without mixing packages from stable and unstable repos.[^1]
+
+```bash
+echo "@community http://dl-cdn.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories
+apk add github-cli@community
+```
+
 [releases page]: https://github.com/cli/cli/releases/latest
 [arch linux repo]: https://www.archlinux.org/packages/community/x86_64/github-cli
 [arch linux aur]: https://aur.archlinux.org/packages/github-cli-git
+[^1]: https://wiki.alpinelinux.org/wiki/Package_management#Repository_pinning
