fix: Render cref elements correctly in text output (#744)

Author: cabo

xml2rfc/writers/text.py

@@ -1321,9 +1321,10 @@ def render_cref(self, e, width, **kwargs):
         source = e.get('source')
         if display:
             text = '\u2028' + mktextblock(self.quote_renderer(e, width, '//', source, None, **kwargs))
+            text += e.tail or ''
             return text
         else:
-            return ''
+            return e.tail or ''
 
     # 2.17.  <date>
     #