feat: tiebreak config function (#1401)

Co-authored-by: Simon Hauser <Simon-Hauser@outlook.de>

doc/telescope.txt

@@ -74,6 +74,20 @@ telescope.setup({opts})                                    *telescope.setup()*
         - "descending" (default)
         - "ascending"
 
+                                              *telescope.defaults.tiebreak*
+    tiebreak: ~
+        A function that determines how to break a tie when two entries have
+        the same score.
+        Having a function that always returns false would keep the entries in
+        the order they are found, so existing_entry before current_entry.
+        Vice versa always returning true would place the current_entry
+        before the existing_entry.
+
+        Signature: function(current_entry, existing_entry, prompt) -> boolean
+
+        Default: function that breaks the tie based on the length of the
+                 entry's ordinal
+
                                     *telescope.defaults.selection_strategy*
     selection_strategy: ~
         Determines how the cursor acts after each sort iteration.