[UmutAlisoglu]

Fixes #178.

Document both JSON datetime range workarounds in the advanced guide: defaults, independent flags, valid millisecond boundaries, exact fallback dates, timezone retention, and process-wide scope. Include runnable examples and explain that the maximum fallback is midnight on December 31, 9999, rather than datetime.max. Clarify that malformed strings and URL literals are outside these workarounds.

Validation:

• Executed both documented code blocks against the current model and checked the two results and strict decoding with the flags disabled; restored original settings afterward.
• Full suite: 314 passed, 93% coverage. Pylint 10/10, Flake8 and diff checks pass.
• Fresh Sphinx HTML build completes with the same five existing warnings before/after (language=None, missing _static, two vendors.rst underlines and its missing toctree entry). Strict -W is not green; this change adds no warning.

Documentation only; no decoder behavior changes. Independent of #327.

Signed off. AI assistance was used to draft and verify this documentation.