[jsfiddle] Update main page to include benchmarkFPS and isRunning
[jsfiddle] Update main page to include benchmarkFPS and isRunning

The docs will help future fiddles be nicer.

Change-Id: I0ce2868a68ecb5bcae7e367408d37a1508425deb
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/281213
Reviewed-by: Kevin Lubick <7cdab2cfab351f23814786ba39716e90eed69047@google.com>
Reviewed-by: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>
Commit-Queue: Kevin Lubick <7cdab2cfab351f23814786ba39716e90eed69047@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot