Improves link detecting regex

bookwyrm/outgoing.py

@@ -294,8 +294,9 @@ def find_mentions(content):
 
 
 def format_links(content):
+    ''' detect and format links '''
     return re.sub(
-        r'([^(href=")]|^)(https?:\/\/([\w\.\-_]+\.[a-z]{2,}(\/[\w\.\-_\/]+)?))',
+        r'([^(href=")]|^)(https?:\/\/(%s([\w\.\-_\/])*))' % regex.domain,
         r'\g<1><a href="\g<2>">\g<3></a>',
         content)