Installing rmagick in Arch Linux

Getting vimdeck requires getting rmagick installed, and that's not straightforward in Arch.
You'll get the well-known found partial imagemagick installation error (MagicWand.h not found).

I finally found this site, which provided me the workaround:

• export PKG_CONFIG_PATH=/usr/lib/imagemagick6/pkgconfig
• gem install vimdeck

Leaving this here in case you want to incorporate it in the README

@tybenz