Improves the maintainability and clarity of the documentation assets by
restructuring directories and refining CSS rules.
- Rename CSS and JavaScript directories for better asset organization.
- Add CSS rules to hide elements with 'bc-docs-hidden' attribute,
enhancing document customization.
- Comment out specific content in CSS header to simplify text display.
- Remove outdated UML mindmap file to clean up unused resources.
- Comment out 'md_in_html' extension in mkdocs configuration to
streamline markdown processing.
Signed-off-by: Glenn Y. Rolland <glenux@glenux.net>
