Setup TypeScript plugin for auto-typegen

[shmuli9]

This PR should enable seamless typgen as you type utilising the custom Typescript plugin

• added a dependency on typescript
• gitignored the type dir
• added the rootDir config to tsconfig

[shmuli9]

We should probably merge #10 before this PR, to fix main branch failing to NPM install

[jacobparis]

Yep these look good, I had to do the same in another project on RR7