Remove avg block time

[Dr-Electron]

Description of change

Removed the average block time. It is misleading. Our block time is dynamic and changes with throughput basically

Type of change

• Documentation Enhancement

Change checklist

• [x] I have followed the contribution guidelines for this project
• [x] I have performed a self-review of my own changes
• [x] I have made sure that added/changed links still work
• [x] I have commented my code, particularly in hard-to-understand areas

[github-actions[bot]]

This pull request has been deployed to Vercel.

Latest commit: 1746408fd812d84985b87fc78481188f4b37f865

:white_check_mark: Preview: https://iota-wiki-p4uvl1ddw-iota1.vercel.app