Updated links to point to corewa.rs

We can't use relative links, because we want them to work in Github pages as
well as on the main repo. Once a separate index.html etc. gets generated we
can make them relative links.

Author: ian-h-chamberlain

README.md

@@ -1,4 +1,4 @@
 # corewa_rs
 A Rust implementation of [Core Wars](http://www.koth.org/index.html).
 
-The implementation is based on [this introductory guide](http://vyznev.net/corewar/guide.html) to Redcode, as well as the [pMARS '94 reference](http://www.koth.org/info/pmars-redcode-94.txt) and an [annotated version](http://corewar.co.uk/standards/icws94.txt) of the ICWS '94 draft.
+The implementation is based on [this introductory guide](http://vyznev.net/corewar/guide.html) to Redcode, as well as the [pMARS '94 reference](http://corewa.rs/pmars-redcode-94.txt) and an [annotated version](http://corewa.rs/icws94.txt) of the ICWS '94 draft.