* Updating the ADR template
Introducing few small sections to the template:
* Summary: IMHO it's very valuable for every reader to quickly see what this ADR is about. Must be short.
* Backwards Compatibility -- each ADR MUST analyze backward compatibility issue. Let's make it clear and put as the ADR subsection.
* Test Cases -- often, when analyzing a problem and implementing a solution, it's very useful to define test-cases. Hence it SHOULD be a part of the template.
Inspiration: Enterprise Ethreum Alliance Proposal [template](https://github.com/EntEthAlliance/EEPs/blob/master/draft/templates/EEP0002-Standards_Proposal_Template.md)
* change Summary -> Abstract
- Added a ADR section to the Contributing.md
- This will streamline and create a central palce for discussions
- Currently conversations are fragmented across platfroms and different forum posts,
the aim here is to move it all to one place and create a document to be used as
reference in the future for why SDK went in this direction.