update for Vite

[AlexErrant]

Hi, thanks for a great library. This PR updates the Readme with instructions for Vite and adds Vite to the test suite.

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Without @surma/rollup-plugin-off-main-thread, the vite build command fails with

❯ npx vite build
vite v5.1.4 building for production...
transforming (1) index.html
<--- Last few GCs --->

[517549:0x572c270]    75048 ms: Mark-sweep 4041.1 (4138.2) -> 4030.7 (4141.4) MB, 1570.5 / 0.0 ms  (average mu = 0.195, current mu = 0.041) task; scavenge might not succeed
[517549:0x572c270]    77747 ms: Mark-sweep 4045.6 (4142.2) -> 4034.5 (4145.2) MB, 2632.7 / 0.0 ms  (average mu = 0.094, current mu = 0.025) task; scavenge might not succeed

<--- JS stacktrace --->

FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory
 1: 0xb7a940 node::Abort() [node]
 2: 0xa8e823  [node]
 3: 0xd5c940 v8::Utils::ReportOOMFailure(v8::internal::Isolate*, char const*, bool) [node]
 4: 0xd5cce7 v8::internal::V8::FatalProcessOutOfMemory(v8::internal::Isolate*, char const*, bool) [node]
 5: 0xf3a3e5  [node]
 6: 0xf4c8cd v8::internal::Heap::CollectGarbage(v8::internal::AllocationSpace, v8::internal::GarbageCollectionReason, v8::GCCallbackFlags) [node]
 7: 0xfbb924 v8::internal::ScavengeJob::Task::RunInternal() [node]
 8: 0xe2c07b non-virtual thunk to v8::internal::CancelableTask::Run() [node]
 9: 0xbe6884  [node]
10: 0xbe9cee node::PerIsolatePlatformData::FlushForegroundTasksInternal() [node]
11: 0x165eb16  [node]
12: 0x1671054  [node]
13: 0x165f47e uv_run [node]
14: 0xabda6d node::SpinEventLoop(node::Environment*) [node]
15: 0xbc1164 node::NodeMainInstance::Run() [node]
16: 0xb35bc8 node::LoadSnapshotDataAndRun(node::SnapshotData const**, node::InitializationResult const*) [node]
17: 0xb3976f node::Start(int, char**) [node]
18: 0x7f46b3fb0083 __libc_start_main [/lib/x86_64-linux-gnu/libc.so.6]
19: 0xabbdee _start [node]
Aborted

However, with @surma/rollup-plugin-off-main-thread, the dev server npx vite dev causes the page to try to load http://localhost:5173/pkg/snippets/wasm-bindgen-rayon-3e04391371ad0a8e/src/undefined which obviously doesn't exist and results in Failed to load module script: Expected a JavaScript module script but the server responded with a MIME type of "text/html". Strict MIME type checking is enforced for module scripts per HTML spec. Possibly related.

Therefore, we conditionally use @surma/rollup-plugin-off-main-thread based on Vite's "mode".

[AlexErrant]

On a separate but related PR, I noticed that vite build fails with the same "JavaScript heap out of memory" error when using wasm-bindgen-rayon in a separate webworker (as was mandatory in <=v1.1.3) even when using @surma/rollup-plugin-off-main-thread. I had to move the code out of the web worker to get vite build to work.

Hypothetically, if I wanted to use a separate web worker, would you know the solution to this? Don't waste too much time if you don't know - I really don't mind not having to spin up another worker. Just asking for the sake of completeness :)

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Edit: Updating Vite to 5.1.6 (released a few weeks after this comment) or higher fixes this issue.

[AlexErrant]

Updating Vite to 5.1.6+ removes the need for @surma/rollup-plugin-off-main-thread. This PR now simply adds a test, which may be useful to guard against regressions.