Merge pull request #137 from chillu/pulls/redirect-contributing

Auto-redirect /contributing to current master docs (fixes #121)

.htaccess

@@ -41,6 +41,10 @@ ErrorDocument 500 /assets/error-500.html
 	RewriteCond %{REQUEST_URI} ^/?framework/en/
 	RewriteRule ^framework/en/(.*)$ /en/$1 [R=301,NC,QSA,L]
 
+	# Docs in /contributing are version agnostic, and should always point to latest
+	RewriteCond %{REQUEST_URI} !(4.0)
+	RewriteRule ^(.*)/(.*)/contributing/?(.*)?$ /$1/4.0/contributing/$3 [R=301,L]
+
 	# DokuWiki rewrite rules: Need to happen before other rules in order to redirect /doku.php?id=<pagename>
 	# to /pagename, which can then be matched by the legacy rewrite rules further down
 	RewriteCond %{QUERY_STRING}          ^(\bid\b=([^&]*)&?(.*)?)