Revise the content of the website

[bchapuis]

According to the Podling Site page, we should revise the structure of the web site to include:

• Project Home Page: the primary entry point to the site; contains project description, news, invitation to join the project.
• License Page: link to the Apache License 2.0.
• Downloads: many projects in incubation release code, and this page describes the releases and has links to the download pages that redirect to Apache Mirror sites.
• Documentation: this page presents the project documentation, including javadoc for Java projects, guides and tutorials, and links to external documentation.
• Committers: a list of current committers on the project. #722
• Mailing Lists: there are several mailing lists that the site visitors might be interested in, and this page contains mailto: links that allow easy subscription (and unsubscription) to any of them.
• FAQ: answers to frequently asked questions.
• Source Code: links to the browsable source repository and git or svn commands to check out the source code.
• Issue Tracking: links to the github issue tracking tool, possibly including frequently-used filters for issue lists. #723
• Dependencies: other projects that this project depends on.
• favicon: the project’s icon in a format suitable for a browser’s address bar. If the favicon is absent, an Apache Feather displays.
• Fix broken links to the examples that have moved to the website repository.

The current web site is generated from the docs directory with jekyll and published on github pages. I suggest we start by revising these markdown web pages.