feat: add ts cmd

[hugomrdias]

This PR adds support for TS type check, .d.ts generations and docs from .d.ts

closes #568
closes #637

[jacobheun]

Can we add some TS guidance to the readme with this? There's nothing in there that covers the support we've added for it, or how to use it.

[vasco-santos]

Overall this looks good! Just found some minor details that should be fixed

[Gozala]

Thanks @hugomrdias this is so great, just one issue that I think that needs to be addressed. Everything else just suggestion or questions.

Iconography of feedback
💭 - Just an idea or an opinion (take it or ignore it as you pleased)
🚨- Problem that should be addressed
❓- Question

[Gozala]

❓Why both typeVersions and types ? Could having both cause some problems ?

[hugomrdias]

types works for the default package export
typeVersions works for atomic internal package exports

[Gozala]

🚨We have discovered couple of issues microsoft/TypeScript#41284, microsoft/TypeScript#41281 with this setup and a workaround by doing following:

Suggested change

	"*": { "src/*": ["dist/src/*"] }
	"*": { "src/*": ["dist/src/*", "dist/src/*/index"] }

[Gozala]

❓Is limiting everything to src deliberate ? And does that not cause problem with package.json that will be falling outside of src ? Also I think I remember seeing some packages that did not have src, but might be conflating with some of the newer IPLD stuff that doesn't use aegir.

[hugomrdias]

using src is an aegir convention

i can't understand the problem with

"types": "./dist/src/index.d.ts",
"typesVersions": {
  "*": { "src/*": ["dist/src/*"] }
}

in the issues above