0.3.0

• In the terminal, the words a stretch adds are drawn in a colour of their own, a different one for
  each stretch you open. The one you opened last is brightest; the others fade a little, and all of
  them fade once you write your next prompt. Each « keeps its stretch's bright colour.
• Closed stretches are underlined in the text's own colour, no longer blue, so colour marks only what
  you opened.
• A « after a rule or a code block goes on a line of its own, in the terminal and in the desktop
  app. Before, it turned the rule into plain dashes or left the code block unclosed.