[DOCUMENT] Add README.md to the Consensus Module

[andrewnguyen22]

Objective

Document Consensus module background, origin document, usage, how to build, how to use, code organization, and any other internals with README.md

Origin Document

This is a standard for all pocket modules in the repository that Consensus is not excepted from.

Hint: Checkout the README.md in other modules for examples.

Goals

• Better document the consensus module

Deliverable

• Add a comprehensive README.md to the Consensus module

General issue deliverables

• Update the appropriate CHANGELOG
• Update any relevant READMEs (local and/or global)
• Update any relevant global documentation & references
• If applicable, update the source code tree explanation
• If applicable, add or update a state, sequence or flowchart diagram using mermaid

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Creator: @andrewnguyen22

[Olshansk]

This one is on me, so I'll take it on that others can edit/build on.

EDIT: will collaborate on this with Gohkan.