fix(parsing): Not all games begin from move 1

Example:https://www.chess.com/game/daily/697768513?move=0

Author: CalvoM

style_predictor/pgn_parser/file_processing/lexer.py

@@ -83,7 +83,7 @@ def lex(self) -> None | list[Token]:
                 case "\n":
                     _ = self.read()
                     self._cr_pos()
-                    if self.peek() == "1":
+                    if self.peek() and self.peek().isdigit():
                         self.lex_movetext()
                         # break
                 case None: