Auto generate gdextension file

[lilizoey]

It should probably be possible to have the .gdextension file get auto generated when we compile the library. which could make things easier for people to set up gdext for the first time.

[pauliesnug]

Would this be in the form of a build.rs script?

[lilizoey]

probably yeah, i havent thought about it a lot so idk the feasibility of doing so.

[Bromeon]

Alternatively, we could set up a project template.

.gdextension is just one of the things to set up. To find its path, we would need a very opinionated directory structure or some sort of heuristic, which can quickly get messy and would get in the way of more exotic setups.

In the future, when gdext is more stable, we can maybe even think about a CLI tool (or just build.rs?) to configure the project. But at the moment it's a bit too much to maintain.