add roadmap to readme

[trkaplan]

@tippi-fifestarr suggested adding this roadmap to the contracts-template repo.

Related Task: Adding context to readme.md
Related PR: #10

I've added my notes:

Proposed Roadmap:

• Update readme
• Go to CityDAO Dev Guild meeting Removed, since I find this is not a part of the projects own roadmap.
• Add Additional Templates w/ Examples Removed. Another template will be added when another type of project we're going to build. But thanks for noting this.
• Update template Keeping the codebase updated is a common thing for all the repos.
• Live workshop demo video on YouTube Good idea!
  • English
  • Chinese English is enough IMO since we expect the developers we want to reach are already comfortable with English.