Most of a gnuplot documentation is missing while its makefiles will
produce docs in a few formats - including html. I guess that this
is a bug in spec file.
Maybe docs should be packaged as a separate gnuplot-docs archive?
This package likely should include also the whole content of 'demo'
subdirectory from gnuplot sources.
The HTML docs were added at some point between 6.1 and 6.2.
As of the 3.7.1-4 build (should be in next rawhide release)
more docs (demo files, latex tutorial, etc.) will be included -
thanks for the bug report.