Define ends and coends

[anshwad10]

Also prove

• The characterization of (co)ends in terms of (co)equalizers and (co)products
• That the end of Hom(𝐹(𝑐),𝐺(𝑐)) is NatTrans(𝐹,𝐺).
• The coYoneda Lemma/density formula/ninja Yoneda lemma