Fix regex

1) Escape the dot
2) Inclusive set instead of exclusion (do not match with ending `?test=lol`)

Note that `\w` is equivalent to `[a-zA-Z0-9_]`. And GitHub apparently also allows `.` and `-` in the usernames and repos.

Author: payne911

README.md

@@ -63,7 +63,7 @@ Once it's activated, the extension will automatically trigger itself whenever yo
 The online tool can be used as a [bookmarklet](https://en.wikipedia.org/wiki/Bookmarklet). To add one manually, press `Ctrl+D` to create a new bookmark and add this code in the URL field:
 
 ```js
-javascript:!function(){if(m=window.location.href.match(/github.com\/([^\/]+)\/([^\/]+)/),m){window.open(`https://useful-forks.github.io/?repo=${m[1]}/${m[2]}`)}else window.alert("Not a GitHub repo")}();
+javascript:!function(){if(m=window.location.href.match(/github\.com\/([\w.-]+)\/([\w.-]+)/),m){window.open(`https://useful-forks.github.io/?repo=${m[1]}/${m[2]}`)}else window.alert("Not a GitHub repo")}();
 ```
 
 When you're viewing a GitHub repo in your browser, you can press the newly created bookmarklet and this will open the online tool for the repo in a new tab.