Update README with build instructions

Author: sbliven

README.md

@@ -1,12 +1,31 @@
 # biojava.github.io
-The new location of the [BioJava homepage](http://biojava.github.io)
+The new location of the BioJava homepage, accessible at either http://biojava.org or http://biojava.github.io.
 
-## Conversion from Mediawiki
+## Running Locally
+
+The website uses [Jekyll](https://jekyllrb.com/) to generate static HTML content from Markdown. This is done automatically for the master branch of github.com/biojava/biojava.github.io, but can also be run locally for testing.
+
+### Installation
+
+Compiling the site locally requires ruby. Install the following gems:
+
+```
+gem install github-pages
+```
 
-Following @peterjc 's instructions how to convert from mediawiki to markdown
+The `github-pages` plugin bundles all gems required for hosting, including the jekyll executable. You can immediately start a server for the content with
 
-https://github.com/peterjc/mediawiki_to_git_md
+```
+jekyll serve --incremental
+```
+
+Note that we aren't yet using bundler ([recommended by github](https://help.github.com/articles/setting-up-your-github-pages-site-locally-with-jekyll/#keeping-your-site-up-to-date-with-the-github-pages-gem)), but this would be a nice feature to configure.
+
+## Conversion from Mediawiki
+
+All content was ported from the prior BioJava wiki following @peterjc 's [instructions and scripts](https://github.com/peterjc/mediawiki_to_git_md).
 
 ## Template
 
-[HTML5 UP](http://html5up.net)
+We use the [HTML5 UP](http://html5up.net) template.
+