docs(org): collapse General and Project description into Overview

docs(org): collapse General and Project description into Overview

Across 28 project pages, replaced the legacy two-tab structure
("* General" + "* Project description") with a single "* Overview"
section so readers see all page content in one scrolling view
without having to click a tab.

Each affected file now has:
  * Overview   — disclaimer at top, then project content directly
  * Repository — license, author, see-also, plus a "Git repository"
                 sub-section with clone URL, snapshot, and gitweb links

Old "* General" custom IDs (used as anchors by the theme) are gone;
back-links in the front matter still point at the category anchors
in index.html, which were not changed.