mdcat-2.15.0

Added

• New mdpick entry point (same binary as mdcat, invoked under that name):
  fuzzy-finds a Markdown file below a directory with fzf,
  honouring .gitignore, then renders the selection through a pager, like
  mdless (GH #21).
• Mermaid diagrams in fenced ```mermaid code blocks now render as PNG images on terminals
  with an image protocol, or as Unicode diagrams otherwise, via
  merman. A theme's mermaid style controls the colour of
  arrows, borders, and text in both the PNG and Unicode rendering, so diagrams match the active
  theme instead of Mermaid's own default (near-black) palette.

Changed

• Raised the minimum supported Rust version to 1.95, required by merman.