Improve the introductive paragraph in the README.

README.md

 # quickref
 
-Quickref generates a website with reference manuals for every
-[Quicklisp](https://www.quicklisp.org) library available.
+Quickref is a global documentation project for Common Lisp libraries. It
+generates a website containing reference manuals for every
+[Quicklisp](https://www.quicklisp.org) library available. The reference
+manuals are generated by [Declt](https://github.com/didierverna/declt).
+
+The official Quickref [website](http://quickref.common-lisp.net) is kept
+up-to-date with Quicklisp. This repository contains the whole infrastructure
+needed to generate your own version of the website.
 
-The reference manuals are generated by
-[Declt](https://github.com/didierverna/declt).
 
 ## Using `quickref`: