TypeGPU endpoints

[aleksanderkatan]

Right now, tgpu, std and data are available on different endpoints. It is not uncommon to see the following in code:

import tgpu from 'typegpu';
import * as d from 'typegpu/data';
import * as std from 'typegpu/std';

I propose that we also export all those from the tgpu same endpoint, so it becomes:

import { tgpu, d, std } from 'typegpu';

Pros that I see:
[+] less lines of code in a typical usage,
[+] we impose a naming convention for d and std,
[+] std already depends on data

[iwoplaza]

[-] major breaking change,

It's not a breaking change if we support both

[-] core does not depend on data (however it is almost exclusively used with data),
[-] data is currently independent from core and std (unless #1486 is merged).

Only the index.ts file would depend on them, and hopefully would be tree shakeable (to be verified)