Add lint rule to validate type descriptions in README

[som-sm]

This PR adds a lint rule that enforces that type descriptions in the README exactly match the first line of their source JSDoc.

readme-jsdoc-lint-rule-demo.mov

The lint caught around 60 mismatches in the existing README file.

[som-sm]

xo.config.js uses the FlatXoConfig type from xo, and FlatXoConfig itself relies on eslint types. However, those eslint types are being incorrectly resolved from @types/eslint, which is causing errors in the config.

I’ve opened a discussion in the ESLint repository about this: eslint/eslint#20704.

[som-sm]

Updated the link to an external link, because otherwise the README description would need manual adjusting because it'd be really complicated to automatically figure out where a particular symbol lives.

If a symbol link is absolutely required, then we'd have to disable the lint-rule for that specific list item and adjust the description manually, as mentioned here:

type-fest/lint-rules/readme-jsdoc-sync.js

Lines 84 to 89 in 8fb539c

	const tagRegex = /\{@link\s+([^\}]+)\}/gv;
	// This simply replaces "{@link SymbolName}" with "`SymbolName`".
	// It doesn't handle captions or external links, for example, "{@link SymbolName | some caption}" simply becomes "`SymbolName | some caption`".
	// For external links, markdown syntax should be used, like "[type-fest](https://github.com/sindresorhus/type-fest)".
	// And for symbols, if just "`SymbolName`" isn't sufficient, then for those specific cases this rule should be disabled.
	jsdocDescription = jsdocDescription.replaceAll(tagRegex, (_, content) => `\`${content}\``);

[som-sm]

Had to switch to eslint type because of this issue.

[som-sm]

This is because XO doesn't seem to lint .md files even if there's an entry for .md files in the config.

[som-sm]

I initially expected only minor discrepancies between the README and JSDoc descriptions, such as typos. However, there were several instances where the two were entirely different. So, I had to review them manually and select the better version. And at certain places, I had to make changes beyond just picking between the two.

As a result, for some types, the JSDoc description has changed, while for some others, the README description has changed. And for some, both have changed.