Beitzah 2: A Tractate about an Egg, Kinda, Sorta

An introduction to this tractate, which is called, "Egg," but is really, fundamentally, about yom tov, the holidays. It therefore has overlap with the tractates of Shabbat, Eruvin, and more. Also: The opening mishnah - when an egg is laid on yom tov... Can you eat it? If so, when can you eat it? If not, what's the rationale for the prohibition? (Including the parallel to Shabbat) Plus, the authorship of the mishnah in this tractate is more complicated, as is evident by apparent contradictory texts, and reflective of more authors than simply R. Shimon.