Add FIP-0045 tutorial

[jennijuju]

not sure where the content should live tho i want something like a tutorial where

• introduce fip0045 concept - like a extendable FIL+ deal
• have a diagram that captures the datacap flow (from -> verified client, allocation, claim, extend, remove expired, via PSD, provecommit/snap, extend and so on)
• tutorial to demo ^, includes the toolings that lotus has (PRs here https://github.com/filecoin-project/lotus/issues?q=+label%3AFIP-0045+)

[jennijuju]

I feel like we can do here

[johnnymatthews]

@TippyFlitsUK @Reiers how often does this come up/how often do people ask questions? And do we think people use it? Trying to figure out how immediate this is.

[TippyFlitsUK]

Hey @johnnymatthews 👋

It doesn't come up too often at the moment but I think that will probably increase following SDM, CDM and potentially re-snapping.

🙏