getting-started(guix): fix grammatical error

src/pages/docs/configuration/getting-started.mdx

@@ -61,6 +61,20 @@ sudo dnf copr enable errornointernet/quickshell
 sudo dnf install quickshell
 ```
 
+## Guix
+Quickshell's source repository works as a channel. Add the following to your channel list:
+
+```scheme
+(channel
+  (name quickshell)
+  (url "https://git.outfoxxed.me/outfoxxed/quickshell")
+  (branch "master"))
+```
+
+Then, you can install the package via `guix install quickshell-git` or by adding `quickshell-git` to your system or home definition.
+
+You can also clone the repository and use `guix shell -f quickshell.scm` to try out the package.
+
 ### Manual build
 See [BUILD.md](https://git.outfoxxed.me/quickshell/quickshell/src/branch/master/BUILD.md)
 for build instructions and configurations.