Bump markdown to 2.1.5 to improve performance and include fixes (#2267)
Bump markdown to 2.1.5 to improve performance and include fixes (#2267)


dart-lang/dartdoc,dart-lang/dartdoc,keertip/dartdoc,keertip/dartdoc,dart-lang/dartdoc,keertip/dartdoc,dart-lang/dartdoc,keertip/dartdoc