Organize the `ltitop` project

[hidmic]

Rationale

For ltitop to be anything but a one-man project, some organization has to be put in place.

Definition of Done

• Add PR template
• Add issue templates
  • Add feature request template
  • Add bug report template
• Add contribution guidelines.
• Add release process.
  • Use semver for versioning.
  • Use Github releases to publish.
• Add code of conduct
• Add roadmap (as project board?)

Additional considerations

Evaluate Github Discussions for contributor exchanges.