v0.21.0

• Action required on macOS 12 Monterey. The macOS binaries now need
  macOS 13 Ventura or later; macOS 12 is not supported. On macOS 12, stay on
  v0.20.0 or update macOS.
• Action required if your config file has a --- line after its
  settings. A config file with more than one YAML document now fails
  startup and --check-config with the file holds more than one YAML document. A single --- at the end of the file counts. Before, the app
  read the first document and ignored the rest without a warning. Delete the
  --- line, and move any settings below it into the first document.
• Security: a crafted link in an issue could make the detail page slow to
  draw. A link with a crafted, very long path in the description of an issue
  or in a comment made each draw of that detail page slow (GO-2026-6218). Only
  someone who can write to a store you open could put it there, and no setting
  prevented it. The release binaries are now built with Go 1.27.2, which fixes
  it.
• Fixed: an empty config file, or one with only comments, stopped
  startup with decode yaml: EOF. Such a file now starts the app with the
  defaults, at the default path and at a --config path alike.
• Fixed: on a 256-colour terminal, the latte theme drew a near-black band
  under the row, the tab or the menu-bar button under the pointer. The band is
  now light grey.
• Fixed: descriptions and comments were drawn in colours the terminal does
  not have. A 16-colour terminal was sent 256-colour codes, and a 256-colour
  terminal was sent true-colour codes in code blocks. Every colour is now drawn
  in the colours of the terminal.
• Fixed: under NO_COLOR, descriptions and comments were drawn in
  colour. They now have no colour, as the rest of the screen.
• Fixed: a paste with Windows line ends added an empty line after every
  line in the issue editor, and two spaces in place of one in a title, a
  filter or a dialog field.
• Fixed: a comment that started with a blank line lost that line when the
  issue editor saved it.
• Changed: under NO_COLOR, bold and reverse text are drawn. Before, no
  text attribute was drawn outside descriptions and comments.
• Changed: on a 256-colour terminal some colours use other palette entries,
  for example the grey of muted text and the selection band.
• Changed: the placeholder of a dialog field is drawn in the grey of muted
  text, as every other placeholder is.