rake tasks to wiki

export-tasks.sh

#!/bin/bash

# Run `rake -D` and format the task descriptions as a
# GitHub-Markdown table (for our Wiki)
# Write the output to tasks.md

touch tasks.md
echo '<dl>' >  tasks.md

bundle exec rake -D |
sed -E '/^rake .*$/{ $! { N;
  s/^(rake .*)(\n)[[:space:]]+(.*)/<dt> \1\2<dd> \3/;
};};
/^$/d;' |
sed -nE '1h; 1!H; ${ g;
  s/\n([^<])/<br>\1/g;
  s/ +/ /g;
  p;
}' >> tasks.md

echo '</dl>' >> tasks.md