install instructions and description update

README.md

@@ -1,15 +1,27 @@
 # Chymeric Gentoo Overlay
 
-An overlay for Gentoo, with various packages chiefly maintained by [TheChymera](https://github.com/TheChymera). 
+An overlay for Gentoo, with various packages used and/or maintained by [TheChymera](https://github.com/TheChymera).
+A number of the ebuilds available from this verlay are regularly copied from external sources (see respective commit mesages), and thus have a different maintainer.
 The repository structure is somewhat based on that of the *gentoo science overlay*, and we also use thin manifests.
 
-## Enable this Overlay
+If you are looking for the neuroscience software packages maintained by [TheChymera](https://github.com/TheChymera), use the [NeuroGentoo overlay](https://github.com/TheChymera/neurogentoo) instead.
 
-Simply add the following commands as root:
+##Install
+
+As per the [current Portage specifications](https://dev.gentoo.org/~zmedico/portage/doc/man/portage.5.html), overlays should be managed via `/etc/portage/repos.conf/`.
+To enable this overlay make sure you are using a recent Portage version (at least `2.2.14`), and crate an `/etc/portage/repos.conf/chymeric` file containing precisely:
 
 ```
-echo >> PORTDIR_OVERLAY+=" /usr/local/portage/chymeric"
-git clone https://github.com/gentoo-science/sci.git /usr/local/portage/chymeric
+[chymeric]
+location = /usr/local/portage/chymeric
+sync-type = git
+sync-uri = https://github.com/TheChymera/gentoo-overlay.git
+priority=8889
 ```
 
+Afterwards, simply run `emerge --sync`, and Portage should seamlessly make all our ebuilds available. 
+Many of our packages are available as live (`*-9999`) ebuilds, and also need manual unmasking in `/etc/portage/package.accept_keywords` before they can be emerged. 
+
+---
+
 *Please report issues via the GitHub tracking system! Please fork and submit pull requests! We're happy to merge!*