Add convenience function that preprocesses a TS then serves the app

[duncanMR]

The preprocessing approach is working a lot better than previous versions in the GEL research environment with terrible performance. My only concern with the new workflow is that I always want to serve the app when I preprocess a TS, so having to run the preprocess command, then copy the serve command and paste it into the shell is a bit inconvenient. This is particularly true with the awful shell performance in GEL, where each step takes a while to complete. I would find it very helpful to have an additional command that combines them, if that doesn't go against the new paradigm too much?

[jeromekelleher]

Don't see any reason not to. Suggestions for names and semantics?

[benjeffery]

How about a --preprocess option to serve?

[jeromekelleher]

Which writes the .tsbrowse file by appending the suffix to the input path? SGTM

[benjeffery]

Yeah, that's the default behaviour of preprocess, we'd match that.

[duncanMR]

That sounds great to me: thanks!