Update documentation for TypeScript 6.0 compiler option changes

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This PR updates TypeScript Website documentation to match the TypeScript 6.0 compiler option defaults, removals, and deprecations described in the 6.0 release notes.

The main goal is to remove stale guidance that describes TypeScript 5.x behavior as the current default. In particular, the docs now make clear that projects should explicitly opt into global @types packages, modern module resolution and emit settings, and supported ECMAScript targets.

Rationale

TypeScript 6.0 changes several long-standing defaults and deprecates older compiler behaviors. Some existing docs still described the previous behavior as current, which could lead users to:

• expect all visible node_modules/@types packages to be loaded automatically;
• rely on rootDir, module, target, and interop defaults from older TypeScript versions;
• use deprecated module emit and resolution modes;
• compile command-line files while expecting tsconfig.json to be ignored;
• follow examples using target: ES5, outFile, legacy namespace module syntax, or no-default-lib directives.

This PR aligns the current reference, handbook, project config, and tutorial content with TypeScript 6.0 while preserving historical release notes.

Changes

• Updated types and typeRoots documentation for the new types: [] default, including the types: ["*"] escape hatch for the old visible-@types enumeration behavior.
• Updated rootDir and related outDir docs for the TypeScript 6.0 default of the directory containing the tsconfig.json.
• Refreshed default-value docs for strict, module, target, noUncheckedSideEffectImports, and libReplacement.
• Added ES2024/ES2025 library documentation and documented that DOM now includes the declarations previously split across DOM.Iterable and DOM.AsyncIterable.
• Updated ES5 target guidance to reflect its deprecation and adjusted active examples to use supported targets or describe ES5 behavior as historical.
• Marked downlevelIteration as deprecated because it only affects ES5 emit.
• Updated module resolution guidance for the deprecation of node/node10, classic, and baseUrl, including migration guidance toward paths, nodenext, and bundler.
• Updated module emit docs for deprecated/removed AMD, UMD, System, none, and outFile workflows, steering users toward external bundlers.
• Updated interop documentation for TypeScript 6.0 defaults around esModuleInterop, allowSyntheticDefaultImports, and alwaysStrict.
• Updated namespace documentation to mark legacy module X {} namespace syntax as deprecated while keeping namespace X {} documented.
• Updated triple-slash directive docs to mark /// <reference no-default-lib="true"/> as deprecated and recommend noLib instead.
• Updated project configuration docs for the new command-line-file behavior: specifying files is now an error when a tsconfig.json would otherwise be loaded unless --ignoreConfig is used.
• Updated generated compiler option pages where visible defaults or descriptions still reflected pre-6.0 behavior.

Validation

• Performed targeted searches for stale current-doc references to the updated 6.0 behaviors.
• Historical release notes were left intact unless they were part of the TypeScript 6.0 release-note source material.

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