v0.1.2

Added

• Diagrams without their tools: with no dot or plantuml installed,
  Graphviz and PlantUML diagrams — in their tab, in Markdown fences and in
  exports — are drawn natively by janalis/viz 0.2. A DOT tab drawn this way is
  the picture alone: node selection, the counts and the cell rendering come
  from dot's layout. What viz leaves to PlantUML, such as an !include of a
  file or a URL, is refused with the reason in the banner.

Changed

• A PlantUML document opens beside its preview whenever Preview PlantUML
  beside its source is on, no longer only when plantuml is found.
• A Mermaid ER relationship is labelled with its role alone, as Mermaid draws
  it (janalis/viz 0.2.2).