Revision 527565

switch kicad-doc from source to pre-built docs

The build process is rather unstable on our asciidoc toolchain, but
then the doc files are completely independent of OS and machine
architecture, so there's nothing which stops us from just taking the
ready-built files from upstream. At the same time this enables two
additional documentation languages (polnish and chinese) - their
build process was even more unstable than the rest in my environment.

PR:		241183
MFH:		2020Q1