Wiki Reorg: Sharding and Asynchronous Backing

[filippoweb3]

See this issue and this google doc for more information about the Wiki reorg.

Refine Page learn-parachains-protocol Content using https://polkadot.network/blog/polkadot-v1-0-sharding-and-economic-security

Add an explanation about asynchronous backing and diagrams explaining the difference between the current situation and async backing.

Some useful material:

• Asynchronous Backing Spec & Tracking Issue paritytech/polkadot#3779
• https://www.youtube.com/watch?v=d1E9FgIMiyU
• https://polkadot.network/blog/polkadot-roadmap-roundup
• https://twitter.com/TheKusamarian/status/1660420952134496257

[CrackTheCode016]

@filippoweb3 @DrW3RK how much detail are we looking to include here? We could go into the implications that this change will bring.

As a sidenote - maybe a page for "Future Polkadot Upgrades" could be warranted? As this is not yet implemented, but still important to highlight and cover IMO.

I have covered all main factors at a high level. The following could be considered a rough TODO on how to expand it:

TODO

• Elaborate on contextual execution and how various contexts relate to it
• Further define the problem of "relay_parent"(s), and reference more exact changes
• Define the possibility of a hard fork, as block time could theoretically be reduced by a change like this on the relay chain?
• Improve the diagram to also show before async backing

[CrackTheCode016]

I'm going to open a new PR which adds this new content under "Future Implementations", meaning this one can likely be closed.

Can be found here: #4871

[CrackTheCode016]

Closed in favor of #4871