use canonical URL

Author: tbrowder

doc/Language/glossary.pod6

@@ -934,7 +934,7 @@ X<|Repository>
 A filesystem under control of a source control management application,
 usually git, that holds the sources for a project, library or
 application. This file, for instance, is in
-L<a GitHub repository|https://github.com/raku/doc>. Repositories store not only
+L<a GitHub repository|https://github.com/Raku/doc>. Repositories store not only
 files, but also history of changes and can be used by the developing or
 writing team for interaction through issues or comments to code.