Prerelease v6.0.0-gimli.0

Summary

Mostly cleanup of the repository to make it more in line with our JavaScript.SDK repository:

• Updated typescript.build version, and copied over build setup (package.json, eslint, mocha, tsconfig)
• Fixed the documentation linter errors that appeared (have not gone through all the code)
• Copied over the workflow, they might have already been identical.
  I also removed some really old leftover code in Unconverted, if we want it back - we can get it from the history.

The real goal of the work was to add a few type predicates for use in the SDK - to not always have to rely on instanceof as that has bit me before. Also I needed a nice way to check if something was a specific concept, so a kind of factory function was added here so we can use it all over the SDK.

Added

• Type predicates isEquatable and isGuid
• Some factory methods createIsConceptAs... to create type predicates for concepts.
• Some more specs for ConceptAs around equality checking.

Fixed

• The information in package.json for the packages (repo, contributors, ...)
• Guid.empty now returns a new instance each time, to prevent any sneaky tampering with it.

Removed

• The typeGuard function. We used it barely in this code, and it didn't make it nicer to read.
• ConceptAs.isConcept was removed, and replaced with an isConcept function that is not exported in the index. It serves no real to others.