Chore/reorg no testing/137 - Subset PR

[saraswatpuneet]

Problem

The separation between DSNP spec and chain level implementation was not clear or easy to see. Link to GitHub Issue: https://github.com/LibertyDSNP/spec/issues/137

Solution

What I/we did to solve this problem

with @wilwade

Change summary:

• Tidy up Roadmap
• DNSP overview to include changelog related to version releases
• ....

[saraswatpuneet]

@wilwade using this PR has placeholder going to put more changes I deem useful, and we can later merge into your branch