docs: add likes attribute to Comment and Submission model doc comments

Author: alythobani

praw/models/reddit/comment.py

@@ -33,6 +33,9 @@ class Comment(InboxableMixin, UserContentMixin, FullnameMixin, RedditBase):
     ``id``            The ID of the comment.
     ``is_submitter``  Whether or not the comment author is also the author of the
                       submission.
+    ``likes``         The user's current vote status on the comment: ``True`` if
+                      upvoted, ``False`` if downvoted, and ``None`` if not voted or not
+                      logged in.
     ``link_id``       The submission ID that the comment belongs to.
     ``parent_id``     The ID of the parent comment (prefixed with ``t1_``). If it is a
                       top-level comment, this returns the submission ID instead

praw/models/reddit/submission.py

@@ -414,6 +414,9 @@ class Submission(SubmissionListingMixin, UserContentMixin, FullnameMixin, Reddit
     ``is_original_content``    Whether or not the submission has been set as original
                                content.
     ``is_self``                Whether or not the submission is a selfpost (text-only).
+    ``likes``                  The user's current vote status on the submission:
+                               ``True`` if upvoted, ``False`` if downvoted, and ``None``
+                               if not voted or not logged in.
     ``link_flair_template_id`` The link flair's ID.
     ``link_flair_text``        The link flair's text content, or ``None`` if not
                                flaired.