add build example to README

Author: vinniefalco

README.md

@@ -1,3 +1,9 @@
+# BoostLook
+
+This is a set of stylesheets, templates, and code for Asciidoctor and
+Antora rendered documentation to give it a uniform look and feel
+befitting the quality of Boost.
+
 Noto font files are covered under the Open Font License:
 
 https://fonts.google.com/noto/use