Document webpack change: feat(SourceMapDevToolPlugin): support append option as a function

[webpack-bot]

A pull request by @snitin315 was merged and maintainers requested a documentation change.

See pull request: webpack/webpack#17252

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Summary

Fixes webpack/webpack#11497
Fixes webpack/webpack#783

🤖 Generated by Copilot at 5b8f508

This pull request adds a new feature to the SourceMapDevToolPlugin and the EvalSourceMapDevToolPlugin that allows the append option to be a function that returns a custom source map URL comment. It also updates the schemas, types, and tests for these plugins to support the new feature.

Details

🤖 Generated by Copilot at 5b8f508

• Allow append option to be a function that returns a custom source map URL comment for SourceMapDevToolPlugin and EvalSourceMapDevToolPlugin (link, link, link, link, link, link, link, link)
• Add a test case for the append function option using some-test.js as an example chunk (link, link, link)
• Throw an error if the append function option is used without the filename option (link)