It’s now possible to embed lichess games (any amount) at the front of the post with the post type. I tried to implement it with a custom tag like {chess game_id} but I think this is not supported by gh pages.
Now it works the following way:
Add this to the front matter (the cryptic stuff is the game id from a lichess game (the part between .org and /black: https://en.lichess.org/tNTJjdFB/black )
games:
- ZfLDSzYr
- tNTJjdFB
It just works.