Detect old sbt version; plus some maintenance

[raquo]

Primarily this is a fix for #17. I tested on MacOS, with sbt 1.6.1, 1.3.3, 1.2.0 and 0.13.18 downloaded from https://www.scala-sbt.org/download.html, and it's working as intended, detecting the error in 1.2.0 and 0.13.18 and printing instructions to fix it:

> [email protected] dev
> vite

[info] welcome to sbt 1.9.7 (Eclipse Adoptium Java 17.0.8.1)
[info] loading settings for project global-plugins from build.sbt,idea.sbt ...
[info] loading global plugins from /Users/raquo/.sbt/1.0/plugins
[info] loading settings for project root from build.sbt,metals.sbt,plugins.sbt ...
[info] loading project definition from /Users/raquo/code/scala/demo/project
[info] loading settings for project root from build.sbt ...
[info] set current project to Laminar Demo (in build file:/Users/raquo/code/scala/demo/)
[error] Expected symbol
[error] Not a valid command: --
[error] Expected 'debug'
[error] Expected 'info'
[error] Expected 'warn'
[error] Expected 'error'
[error] Expected 'addPluginSbtFile'
[error] --batch
[error]   ^
error when starting dev server:
Error: sbt invocation for Scala.js compilation failed with exit code 1.
Cause: Your sbt launcher script version is too old (<1.3.3).
Fix: Re-install the latest version of sbt launcher script from https://www.scala-sbt.org/
    at ChildProcess.<anonymous> (file:///Users/raquo/code/js/vite-plugin-scalajs/dist/index.js:29:24)
    at ChildProcess.emit (node:events:513:28)
    at maybeClose (node:internal/child_process:1091:16)
    at Socket.<anonymous> (node:internal/child_process:449:11)
    at Socket.emit (node:events:513:28)
    at Pipe.<anonymous> (node:net:313:12)

I ran it on my laminar-demo project, everything seems fine. Tests pass.

Let me know if you want the error reworded or something.

I also made the following rather trivial changes in separate commits, but let me know if you want separate PRs for them.

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Added common IDE and OS files to .gitignore.

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Ran npm audit fix because it was reporting vulnerabilities in transient dependencies. It just updated some versions in package-lock.json, I skimmed through the changes, and I don't see anything controversial in there.

# npm audit report

get-func-name  <2.0.1
Severity: high
Chaijs/get-func-name vulnerable to ReDoS - https://github.com/advisories/GHSA-4q6p-r6v2-jvc5
fix available via `npm audit fix`
node_modules/get-func-name

postcss  <8.4.31
Severity: moderate
PostCSS line return parsing error - https://github.com/advisories/GHSA-7fh5-64p2-3v2j
fix available via `npm audit fix`
node_modules/postcss

vite  4.1.0 - 4.1.4
Severity: high
Vite Server Options (server.fs.deny) can be bypassed using double forward-slash (//) - https://github.com/advisories/GHSA-353f-5xf4-qw67
fix available via `npm audit fix`
node_modules/vite

3 vulnerabilities (1 moderate, 2 high)

To address all issues, run:
  npm audit fix

[sjrd]

Thanks :)