Cleanup spacemesh github repos wikis (WIP)

[avive]

Remove all outdated mds from wikis in prep for new wiki in the code repo.
Apply to all Spacemesh repos with the goal of not having outdated information in any repo.

[avive]

go-spacemesh is wip

[avive]

product repo is a wip

[avive]

There's still lots of outdated go-spacemesh wiki pages which are probably only confusing newcomers. Let's please get rid of these as the protocol docs supersede them.

[avive]

@lrettig - let's coordinate between us who's going to do this.