[Users] LiteHtml Viewer Dependency Note in 'INSTALL' File

[Dustin Miller]

I'm working on upgrading some of my systems to Claws Mail 3.17.4 and am
grateful to everyone who has been working to improve the program.

One thing I'm looking forward to using is the LiteHtml Viewer plugin.
However, on an initial run of 'configure' it reported that this plugin
was disabled due to a missing dependency. After poking around for
awhile, I got lucky and figured out that the dependency required is
'libgumbo' (an HTML5 parser library).

I'm guessing it would be quite helpful if this plugin name and its
dependency info could be added to the 'Additional libraries or
programs' section of the 'INSTALL' file that's included with the
'released' package available for download from the website. Would one
of you developers who has access/authorization to the repo/website be
able to do this at some point?

Let me know if you want me to report this as a bug (enhancement) or if
there is a reasonably accessible way that I could make this change
myself.

Thanks again to each of you who contributes to the ongoing development
of CM.

Dustin