Enhancing contributor DX

Making the DX better

Monorepo watch mode for BuckleScript based on https://github.com/fhammerschmidt/bucklescript-monorepo
Esy config for OCaml LSP
Better demo

Unfortunately there are still a couple of problems to solve in this PR

[ ] Redemon is watching lib/ from the packages and it's causing an infinite loop. Quite weird because it's the same setup we have been using internally at Astro and works pretty fine.
[x] That is causing the Webpack in demo/ it seems to not be able to collect the dependencies properly
[x] Gotta get rid of graphql_ppx and use the new community one
~[ ] Use https://github.com/zth/graphql-client-example-server instead for GraphQL Demo~ no graphql for now, using reason-async-hook
[x] helpers for composing validators
[x] inline records for validators
[x] merge with #151

rescriptbr / reform