Add tsdoc comments for Blitz functions inside VSCode

### What do you want and why?

Currently developers have to rely on the [blitz docs](https://blitzjs.com/docs/contributing) for documentation about function and parameter definitions. This means we have to context switch to the browser, visit the webpage, copy and paste the function name and use the search functionality.

We should use jsdocs to embed the documentation from the wiki inside VSCode.

For example pressing command and hovering over `useRouter` doesn't show anything in VSCode:

Here's how the Chakra functions look when we press command and hover:

Note the href will also save a lot of time as it links directly to the wiki.

### Possible implementation(s)

Using jsdocs