[Governance] Refining FLIP for Dynamic Inclusion Fees

[Tonix517]

As a follow-up to #12 - refined the FLIP per the feedback from our recent meetings and discussions.

Updates:

• [X] added number of signatures into the equation and re-fitted the equation with the existing data
• [X] added a Proposal section
• [X] fixed all math terms to make it consistent with other FLIP
• [X] truncated all multi-digit numbers into limited precision for more readability
• [X] reran all existing analysis and got new numbers
• [X] added one more item for Limitation section
• [X] misc. styling fixes

Links https://github.com/onflow/flow-go/issues/3451 https://dapperlabs.slack.com/archives/C015G65HR2P/p1666029485953369