When converting all of the samples to use the snippet tool, I encountered some bugs/shortcomings:

1. The document production took 90 minutes, since the snippet tool was being invoked from the command line each time. I fixed this by snapshotting the executable before running, so it's down to 7 minutes.

2. The sample code was not being properly escaped by the snippet tool, so generics were causing issues in the HTML output. It is now quoted.

3. Code examples that used languages other than Dart were not supported. Anything that highlight.js was compiled for dartdoc with is now supported.

4. The comment color for highlight.js was light grey on white, which was pretty unreadable. It's now dark green and bold.