Improve accessibility of project/tutorial project templates

Currently, new users must clone the `component-docs` repo, head to a specific sub-directory *then* attempt to build projects.

It would be ideal if there were easier ways to download and set up resources to walk through the tutorials.

While we probably want to *avoid* building custom tooling in every possible language (different languages have different scaffolding mechanisms), we need a solution that is a bit less nested.

There were several good suggestions made, one of which being a single repo that contains all the languages at the top level (thanks @mkatychev), which is a bit easier to clone and filter out.

Another suggestion is that this could actually be a part of #219 -- having a "Current" release that always contains tarballs of the current code for any given language might make it easy to download and extract (ex. `rust-starter.zip` or `js-starter.zip`).

We could also rely on language-specific templating functionality, but this would likely require ensuring that it *exists in the first place* for all related languages (i.e. `cargo component new`, `jco new`, `componetize-py new`, etc), or in a shared tool like `wit-bindgen` which may not be feasible.