Update README.md

Fix markdown

Author: vxbinaca

README.md

@@ -41,7 +41,9 @@ Then run:
 ```
 To use a nightly yt-dlp build, inject it into your yt-dlp virtual environment:
 
-`pipx inject yt-dlp "yt-dlp[default,curl-cffi] @ https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/download/[NIGHTLY TAG]/yt-dlp.tar.gz" --force`
+```
+pipx inject yt-dlp "yt-dlp[default,curl-cffi] @ https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/download/[NIGHTLY TAG]/yt-dlp.tar.gz" --force
+```
 
 Where `[NIGHTLY TAG]` would for example be `2025.10.11.232807` in [this yt-dlp release](https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/tag/2025.10.11.232807).