Add TypeScript compatibility table

[the-spyke]

It's quite hard to find which version on runtypes I need if I have X version of TypeScript and vise versa. It would be nice to have a compatibility table in the readme. For example like here: https://github.com/colinhacks/zod#typescript-requirements

[yuhr]

That should be, definitely. Actually we don't have enough resource to gather accurate info for old versions, but the version number of typescript in package.json can be a guide for it. I'm willing to maintain a comatibility table in README.md for recent and further versions from now on.