Document webpack change: enhanced-resolve@5.10.0

[webpack-bot]

A pull request by @vankop was merged and maintainers requested a documentation change.

See pull request: webpack/webpack#16001

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What kind of change does this PR introduce?

update deps

Did you add tests for your changes?

there are tests in enhanced-resolve

Does this PR introduce a breaking change?

no

What needs to be documented once your changes are merged?

add resolve.extensionAlias which allows to alias extensions to new extensions (multiple alternatives).

Example

externsionAlias: {
  ".js": [".ts", ".js"],
  ".mjs": [".mts", ".mjs"]
}

It's an "alias" so not including the original extension will only alias the request to the new extension, which means the original extension is no longer used.

[snitin315]

I'll document this.