Fix a link name

Author: bbatsov

clojure-mode.el

@@ -76,7 +76,7 @@
   "Major mode for editing Clojure code."
   :prefix "clojure-"
   :group 'languages
-  :link '(url-link :tag "Github" "https://github.com/clojure-emacs/clojure-mode")
+  :link '(url-link :tag "GitHub" "https://github.com/clojure-emacs/clojure-mode")
   :link '(emacs-commentary-link :tag "Commentary" "clojure-mode"))
 
 (defconst clojure-mode-version "5.8.0-snapshot"