gplugin/gplugin

Make sure our references to gplugin docs have their required trailing slash

2021-09-28, Gary Kramlich
ac20fdcbfd10
Make sure our references to gplugin docs have their required trailing slash

Testing Done:
Built the docs and verified the links were now corrected.

Reviewed at https://reviews.imfreedom.org/r/957/
if get_option('rs')
add_languages('rust')
subdir('tests')
endif # rs