[MRG + 1] DOC adding :user: role to whats_new (scikit-learn#7818)

* DOC adding :user: role to whats_new

* DOC correcting the improper username

* DOC adding exceptions for ImportError in sphinx_issues.py

* DOC added import for split_explicit_title

* DOC reverting to the old format for core devs

* DOC reverting changes for more users

* DOC removing extra lines and blank lines

* DOC Adding missing link target for user

* DOC fixing more links

* DOC adding missing links for new contributions

* DOC adding space before brackets in the user links

* DOC reverting a wrong change

* DOC adding final changes

Author: dalmia

doc/sphinxext/sphinx_issues.py

@@ -24,6 +24,7 @@
 
 try:
     from docutils import nodes, utils
+    from sphinx.util.nodes import split_explicit_title
 except ImportError:
     # Load lazily so that test-sphinxext does not require docutils dependency
     pass
@@ -45,13 +46,20 @@ def user_role(name, rawtext, text, lineno,
     """
     options = options or {}
     content = content or []
-    username = utils.unescape(text).strip()
+    has_explicit_title, title, target = split_explicit_title(text)
+
+    target = utils.unescape(target).strip()
+    title = utils.unescape(title).strip()
     config = inliner.document.settings.env.app.config
     if config.issues_user_uri:
-        ref = config.issues_user_uri.format(user=username)
+        ref = config.issues_user_uri.format(user=target)
+    else:
+        ref = 'https://github.com/{0}'.format(target)
+    if has_explicit_title:
+        text = title
     else:
-        ref = 'https://github.com/{0}'.format(username)
-    text = '@{0}'.format(username)
+        text = '@{0}'.format(target)
+
     link = nodes.reference(text=text, refuri=ref, **options)
     return [link], []