CONTRIBUTING.md: Drop dependency and build instructions

They are redundant with README.md, and haven't been kept up to date.
For example, the CONTRIBUTING.md dependencies are missing the xmlto
dependency.  Rather than try to maintain this information in two places,
just refer contributors to the README and keep the CONTRIBUTING doc
focused on high level process.

Signed-off-by: Daniel Burgener <[email protected]>
Acked-by: James Carter <[email protected]>

CONTRIBUTING.md

@@ -23,14 +23,7 @@ using a custom policy please include it as well.
 
 ## Compiling
 
-There are a number of dependencies required to build the userspace
-tools/libraries. On a Fedora system you can install them with yum:
-
-    # yum install audit-libs-devel bison bzip2-devel dbus-devel dbus-glib-devel flex flex-devel flex-static glib2-devel libcap-devel libcap-ng-devel pam-devel pcre2-devel python-devel setools-devel swig ustr-devel
-
-The tools and libraries can be built and installed under a private directory from the top level with make, e.g.
-
-    $ make DESTDIR=~/obj install install-pywrap
+See README.md for instructions on how to compile and test this project.
 
 ## Contributing Code