Local development steps

[julesvirallinen]

Hi! I'm looking to tackle a bug, but I'm having trouble running the plugin locally.

I'm ready to add local development steps to the README once I get it up myself.

Right now I'm getting the following errors when trying to run npm run dev locally

 > src/ui/suggest.ts:2:62: error: Could not resolve "@popperjs/core" (mark it as external to exclude it from the bundle)

I think the problem might be a node version conflict. What node version was this developed in? I can add it to.nvmrc to resolve it for future contributors if needed.

EDIT: the node version used seems to be 16 (from @types/node)! The problem above seemed to be from my laptop however, as on my other laptop it worked swimmingly immediately!