[debug-toolbar/display_source_code] change link display from "<>" to "[source]"
It is way more explicit and understandable and doesn't take that much place.
extend-diff-ignore = "^(__pkginfo__\.py$|doc/_themes/cubicweb/static/(logo-cubicweb-small\.svg|cubicweb\.ico|logo-cubicweb\.svg)$|cubicweb\.spec$|setup\.cfg$|cubicweb/misc/cwfs)"