Missing content for market usage details

[seanmakesgames]

Problem

Details about how the market works are missing from the wiki.

Context

Stuff like upgrade stacking.
https://discord.com/channels/229545531104296960/229575538975440896/1205160584048541797

[matr1x-hackmud]

This seems most appropriate to make as a guide, alongside some of the other game mechanics. A lot of how the market works also overlaps with how upgrades work, which could either be a guide or have an objective page about the overarching upgrade mechanics

[danswann]

As one option: it is possible to make the Upgrades thing in the navbar its own link, independent of selecting any of the dropdown items. That could go to an upgrade overview page.