Consolidate around ast-grep

[43081j]

we currently have both jscodeshift and ast-grep.

the former isn't very well maintained anymore, but the two also have vastly different approaches to codemods.

if we settle on one, we can reduce the install size massively. even though we have abstractions around the underlying codemod tools, this might also make our API simpler and easier to maintain

i think we should settle on ast-grep

cc @thepassle and @outslept in particular

[gameroman]

I agree with this, I will try to help migrate existing ones to ast-grep