Update technical docs for tracks config
Description
Update technical docs for how to configure tracks in VISUAL. Relates to #1921 (closed) / !605 (merged).
Relevant page: docs/technical/uioptions.md
(under section "IGV in VISUAL")
Should be branched off and merged into 1974-update-docs-for-v1-16-0
branch (!612 (merged))
Edited by Morten C. Eike