feat(js): initial directories (#5671)

* feat(js): initial directories

* chore(ts): scaffold phoenix ts packages (#5701)

* chore(ts): scaffold phoenix ts packages

* add prettier and eslint and ci

* fix(ts): remove explicit prebuild command

* chore(js): add rudamentary types for experiments

* add types

* fix

* Update js/packages/phoenix-client/src/types/experiments.ts

Co-authored-by: Parker Stafford <52351508+Parker-Stafford@users.noreply.github.com>

* feat(js): Produce ESM build artifacts

* Delete unused package stubs

* Bump baseline esm config target and configure aliasing

* Add config tests

Had to break out config merging logic so that it was testable

---------

Co-authored-by: Parker Stafford <52351508+Parker-Stafford@users.noreply.github.com>
Co-authored-by: Parker Stafford <parker.stafford92@gmail.com>
Co-authored-by: Tony Powell <apowell@arize.com>