Improve and standardize documentation for all indicators and modules

[xgboosted]

Justification: Comprehensive documentation improves usability, onboarding, and community contributions.
Goals: Standardize and expand docstrings, usage examples, and Sphinx documentation for all indicators and modules.
Implementation Plan:

• Audit all indicator modules for missing or incomplete docstrings.
• Add/standardize docstrings with argument descriptions, return types, and usage examples.
• Update Sphinx docs and README with accurate indicator counts and category breakdowns.
  Test Plan:
• Build Sphinx docs and validate coverage.
• Add CI/CD step for docstring and documentation checks.
• Validate with sample scripts and user feedback.

[BradKML]

Automate the documentation process with something like Qwen3 (empathic writer) or Kimi K2 (persuasive writer). Refine by human feedback if necessary, and keep it on standard template formats.