Add top-level help file for the plugin

[TheCodeArtist]

Signed-off-by: TheCodeArtist cvs268@gmail.com

Fixes #44

[codecov-io]

Codecov Report

Merging #47 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master      #47   +/-   ##
=========================================
  Coverage     64.93%   64.93%           
  Complexity      149      149           
=========================================
  Files            15       15           
  Lines           750      750           
  Branches         99       99           
=========================================
  Hits            487      487           
  Misses          225      225           
  Partials         38       38

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[TheCodeArtist]

Can someone please confirm that this change actually fixes issue #44?

I have added the help file for the plugin source as help.html
based on the documentation in https://wiki.eclipse.org/Basic_guide_to_Jelly_usage_in_Hudson
that says...

You can add top-level plugin help, e.g. on the job configuration page,
by providing help.html or help.jelly in the src/main/resources/path/to/plugin/PluginName/ directory.