Github Discussions to have convos around book

[tesla809]

Excellent book so far!

Setting up a Github discussion for this repo would help with the following:

• creating community
• creating a steady funnel of possible contribtoooooors
• extra eyes for editing
• adding more context and nuance to the subject
• Github discussions are indexable by Google, so more convo would boost the project's SEO
• create a space to onboard more newbies to learn about ETH2.
• Facilitates coordination around the creation and updating of the book in an easier way than Telegram.

Additionally, folks discussing parts of the book would help them learn the subject even further.