a replacement for lerna run --stream --parallel

motivation:

• runs the first compile in order, spawning additional workers when appropriate
  • when projects have inter-dependencies, ordering is important
  • spawning dozens of tsc instances simultaneously slows things to a crawl
• avoids vm overhead of running tsc per-project

of course, the tradeoff is that it loses any speedup from parallel compilation

usage:

• npm i -g multi-watch-tsc / yarn global add multi-watch-tsc
• in your workspace, run TSC_NONPOLLING_WATCHER=1 multi-watch-tsc packages/*/tsconfig.json