Wiki: escape pipes in table-cell [[Target|Display]] links (fixes broken nav links)
Aliased wiki-links inside markdown table cells collided with the table's own | column delimiter, so GitHub split the cell and rendered the link as literal '[[Target' text (Home 'Start here'/HOWTO/Subsystems/Reference tables, the Index page list, and a few reference pages). The pipe is now escaped as backslash-pipe, which both GitHub's wiki and Obsidian require inside a table cell; list-context links (the sidebar) were already fine and are untouched. 56 links across 8 pages.
Wiki update — v5.9.112, maintenance pass, new reference pages, source-tree reorg, full version history up to latest release
Wiki update - v5.9.88 animated GIFs, new HOWTO guides, glossary, FAQ, debugging, contributing
New pages: Contributing, Debugging, FAQ, Glossary, HOWTO-Add-a-GUI-application,
HOWTO-Add-a-shell-command, HOWTO-Add-a-system-call, HOWTO-Write-a-userspace-program,
Kernel-Data-Structures, Troubleshooting, Wiki-Conventions.
All existing pages updated through v5.9.88 (animated GIF playback, image decoders).