Document current and planned smart contracts

[nikipapadatou]

Collect and document all smart contracts currently used or planned across Swarm.
This task focuses purely on information gathering, not proposing changes.

For each, include:

• Name / identifier
• Repository
• Short description of purpose and usage
• Any documents related or documentation (if applicable)

The deliverable should be a document summarizing the above information, linked to this issue.

[0xCardiE]

Docs would be included in repo as usual and been working on them here
#299