Document webpack change: perf: improve FlagDependencyExportsPlugin for large JSON by depth

[webpack-bot]

A pull request by @hai-x was merged and maintainers requested a documentation change.

See pull request: webpack/webpack#19058

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What kind of change does this PR introduce?

perf only for development mode

Fixes webpack/webpack#18458

Did you add tests for your changes?
Yes

Does this PR introduce a breaking change?
No

What needs to be documented once your changes are merged?

Add two options to https://webpack.js.org/configuration/module/#moduleparser

for json

• parse - Function that executes for a module source string and should return json-compatible data. Type ((input: string) => any), for For example we can use toml parser

const toml = require("toml");
 
module.exports = [
	{ 
		module: {
			rules: [
				{
					test: /\.toml$/,
					type: "json",
					parser: {
						parse(input) { 
							return toml.parse(input);
						}
					}
				}
			]
		}
	}
];

• exportsDepth - The depth of json dependency flagged as exportInfo. In dev mode - 1, in prod - Infinity, Type number

[hai-x]

I'll follow up later