Add method to get title of post (#976)

Co-authored-by: Tejas Chauhan <tejas.chauhan@kevit.io>
Co-authored-by: Alexander Graf <17130992+aandergr@users.noreply.github.com>

instaloader/structures.py

@@ -128,6 +128,14 @@ class Post:
         """The mediaid is a decimal representation of the media shortcode."""
         return int(self._node['id'])
 
+    @property
+    def title(self) -> Optional[str]:
+        """Title of post"""
+        try:
+            return self._field('title')
+        except KeyError:
+            return None
+
     def __repr__(self):
         return '<Post {}>'.format(self.shortcode)