WASM support

[bbarker]

bevy_voxel_world currently doesn't support WASM builds:

   Compiling bevy_voxel_world v0.3.3
error[E0308]: mismatched types
   --> /home/bbarker/.cargo/registry/src/index.crates.io-6f17d22bba15001f/bevy_voxel_world-0.3.3/src/voxel_world_internal.rs:289:38
    |
289 |             .insert(ChunkThread::new(thread))
    |                     ---------------- ^^^^^^ expected `Task<ChunkTask>`, found `FakeTask`
    |                     |
    |                     arguments to this function are incorrect
    |
    = note: expected struct `Task<chunk::ChunkTask>`
               found struct `bevy_tasks::single_threaded_task_pool::FakeTask`
note: associated function defined here
   --> /home/bbarker/.cargo/registry/src/index.crates.io-6f17d22bba15001f/bevy_voxel_world-0.3.3/src/chunk.rs:28:12
    |
28  |     pub fn new(task: Task<ChunkTask>) -> Self {
    |            ^^^ ---------------------

For more information about this error, try `rustc --explain E0308`.
error: could not compile `bevy_voxel_world` (lib) due to previous error
2023-12-10T01:56:25.435082Z ERROR ❌ error
error from HTML pipeline

Caused by:
    0: error from asset pipeline
    1: error during cargo build execution
    2: cargo call returned a bad status

If it were to work, the directions for building would be something like this, based on the template:

### Building for the web (WASM)

        * requires [trunk]: `cargo install --locked trunk`
        * requires `wasm32-unknown-unknown` target: `rustup target add wasm32-unknown-unknown`
        * Start the web build: `trunk serve`
        * this will serve your app on `8080` and automatically rebuild + reload it after code changes

### Deploy web build to GitHub pages
 1. Trigger the `deploy-github-page` workflow
 2. Activate [GitHub pages](https://pages.github.com/) for your repository
     1. Source from the `gh-pages` branch (created by the just executed action)
 3. After a few minutes your game is live at `http://username.github.io/repository`

To deploy newer versions, just run the `deploy-github-page` workflow again.

Note that this does a `cargo build` and thus does not work with local dependencies. Consider pushing your "custom Bevy fork" to GitHub and using it as a git dependency.
 

# Known issues

Audio in web-builds can have issues in some browsers. This seems to be a general performance issue and not due to the audio itself (see [bevy_kira_audio/#9][firefox-sound-issue]).