Relative to file requires

[centau]

Currently when reusing modules composed of multiples files in different projects, the require within the modules break since the require paths assume that the module is the root directory, which isn't the case when they are being used in another project.

Being able to relatively require other files would make modularity with luau files much easier.

[vegorov-rbx]

We have started work to support relative string requires and a few extra features.

[vrn-sn]

@centau - Relevant RFC.

[zeux]

The original issue for this is #102 so I'll close this one as a duplicate.