use the locally installed keys.*.html instead of connecting to the web
Originally reported in Debian: [https://bugs.debian.org/850771](https://bugs.debian.org/850771).
The Inkscape "Help" menu needs internet access to work.
This is annoying for airgapped users.
IIRC most of the menu items link to non-DFSG content, but one menu item is easy to fix: inkscape_help_keys.inx.
The inkscape source package contains the same content.
Please install these somewhere like `file:///usr/share/doc/inkscape/html/` or `file:///usr/share/inkscape/doc/html/`, and patch inkscape_help_keys.inx to point to them instead of http://inkscape.org/doc/keys092.html.
There is one problem with language detection. I presume the HTTP version does this via [Accept-Language](https://en.wikipedia.org/wiki/Content_negotiation).
The keys.*.html files don't link to one another, so inkscape_help_keys.inx or launch_webbrowser.py might need to be extended provide equivalent functionality based on $LANG?
#### Inkscape Version and Operating System:
- Inkscape Version: all versions till now :)
- Operating System: all Linux.
issue