v0.1.0

Initial release of the uml-drawing skill.

Added

• uml-drawing skill: build a correct UML class diagram through BESSER
  B-UML — from a description or from existing code the agent reads — and
  deliver it either as embedded B-UML code in a Markdown doc or as a
  rendered SVG/PNG image.
• Automated image rendering — the agent can produce the image itself with a
  single call to BESSER's headless B-UML → SVG endpoint
  (POST /besser_api/get-svg): no browser, no manual steps. A hand-tuned
  export from the BESSER web editor stays
  available for when the layout matters.
• Bundled references/class-diagram.md
  — the full class-diagram metamodel reference (classes, attributes,
  enumerations, associations, association classes, generalizations,
  generalization sets, methods, validation).
• Scope is deliberately narrow for now: class diagrams only, always via
  BESSER B-UML.
• .github/workflows/release.yml — auto-creates a GitHub Release from the
  matching CHANGELOG section when a v* tag is pushed.