Add first class Javascript/Typescript support to the Mill build tool

[monyedavid]

This pr implements the examples for jslib/module.

#3927

Key Changes:

• handle usage of resources files in bundled and non-bundled environments
• handle custom-resources usage
• Standard resource files in @<module-name>/resources or custom resources files in user defined custom resource path can be imported globally@<module-name>/resources-directory
• allows for access to resources defined in dependent modules
• allows for access to resources in bundled code and environment
• allows for access to resources define in /test
• updated build script to handle multiple resources directories

Implements Task generatedSources

• imported via @generated/generated-file-name

Note:

For example/javascriptlib/module/3-override-tasks/, the foo directory needs to exist, hence the file foo/readme.md, code sources are generated from its .mill file

Checklist

• example/jslib/module
  • common-config/
  • resources/
  • custom-tasks/
  • override-tasks/
  • compilation-execution-flags/
  • executable-config

[lihaoyi]

I've taken a glance at this and it isn't really sufficient. Please look at the Java/Kotlin/Scala equivalents of these pages and see what is expected

[lihaoyi]

example.javascriptlib.basic[3-custom-build-logic].local.test appears to be failing in CI

[monyedavid]

Fixed failing tests

[lihaoyi]

Some last few comments, otherwise just need to flesh out the documentation for all the build.mill files and include them in a page in docs/modules/ROOT/pages/javascriptlib/linting.adoc

[lihaoyi]

I think the code looks good enough for now. Please fix up the docs to include proper english explanations of every example, and ensure that the test-docs CI job passes, then we can merge it