[DOCS] Begin documenting `MinBaseFee` feature

[geoknee]

Description

We would like to start work documenting this feature currently in development:

Acceptance criteria

• Chain Operators need to be made aware that setting the minimum too high may have negative impacts on users (making transactions harder to get included).
• Chain operators need to understand the manner by the parameter is set using a base 2 logarithm.

User stories

Resources and support

ethereum-optimism/design-docs#295
SME: @geoknee, @joshklop , @sebastianst

Action items