* Added new guide on CorDapp Constraints Migration procedures.
* Apply formatting and upper/lowercase changes.
* Updated following PR review feedback from RGB and MH.
* Minor clarification and cleanup.
* Clarify step to ensure there is only one version ("signed") of the same Contracts CorDapp in the nodes /cordapp folder
* Incorporating feedback from SS.
* Replaced "propagate" with "transition".
Adjust terminology to be consistent.
* Removed confusing statement.
* Document CorDapp upgradeability guarantees.
* Incorporating feedback from RGB.
* Incorporating feedback from MH.
* Minor updates following re-review by RGB
* Updates following review by MH.
* Include new document in index.
* Incorporating review feedback from MH.
