Merge pull request #147 from vshabanov/fix-github-link

Fixed the GitHub link in the sponsors section.

Author: myShoggoth

donations/sponsors/github.markdown

@@ -2,6 +2,6 @@
 title: GitHub
 logo: /assets/images/sponsors/github/github-683.png
 srcset: /assets/images/sponsors/github/github-200.png 200w, /assets/images/sponsors/github/github-400.png 400w, /assets/images/sponsors/github/github-683.png 683w
-externalUrl: https:/github.com/
+externalUrl: https://github.com/
 level: Monad
 ---