README.txt: suggest calling "egg_info", not "install"
README.txt: suggest calling "egg_info", not "install"

.. because "install" requires root privileges, and is unnecessary for
developing Skylines.

TobiasLohner/SkyLines,Harry-R/skylines,dkm/skylines,RBE-Avionik/skylines,Turbo87/skylines,skylines-project/skylines,Harry-R/skylines,shadowoneau/skylines,TobiasLohner/SkyLines,kerel-fs/skylines,Turbo87/skylines,shadowoneau/skylines,snip/skylines,shadowoneau/skylines,RBE-Avionik/skylines,shadowoneau/skylines,skylines-project/skylines,skylines-project/skylines,snip/skylines,TobiasLohner/SkyLines,Turbo87/skylines,dkm/skylines,Turbo87/skylines,Harry-R/skylines,kerel-fs/skylines,skylines-project/skylines,kerel-fs/skylines,dkm/skylines,Harry-R/skylines,RBE-Avionik/skylines,snip/skylines,RBE-Avionik/skylines,dkm/skylines