Update how-to-build info

Author: wohali

README.md

@@ -5,6 +5,15 @@ You can view the latest rendered build of this content at:
 
     http://docs.couchdb.org/en/latest
 
+# Building this repo
+
+Install Python 2.7+ and pip. Then:
+
+```sh
+$ sudo pip install Sphinx sphinx_rtd_theme
+$ make html # builds the docs
+$ make check # syntax checks the docs
+```
 # Feedback, Issues, Contributing
 
 General feedback is welcome at our [user][1] or [developer][2] mailing lists.
@@ -16,3 +25,4 @@ with issue reporting or contributing to the upkeep of this project.
 [2]: http://mail-archives.apache.org/mod_mbox/couchdb-dev/
 [3]: https://github.com/apache/couchdb/blob/master/CONTRIBUTING.md
 
+