Drop the symlinks to allow differences between top level directory
and V2, allowing links from V2 content to other V2 topics.
Move what-is-lava to rsti to silence duplicated heading warnings.
Replace a PNG figure with SVG.
Fix broken glossary link for job context and add missing escape
for wildcard in Debian table.

Change-Id: Ie7a954d9c8ea7a9a352caae4be531188a7abd70b