optimize: investigate whether we are obtaining the maximum performance from our folding techniques

[thor314]

We are currently exploring folding techniques to reduce memory for proving aes-gcm. Document these techniques as exists, and point direction for further optimization paths. Est 2-5h work.

[thor314]

working on a prototype with waylon at https://github.com/thor314/prototype-circom-fold

[0xJepsen]

How is the prototype coming?