Add new main page

New index page for the data.hisparc.nl page.
This should be used to refer users to the right page

- status/summaries
- jsparc data analysis
- sapphire data analysis
- ... etc.. HiSPARC data stuff..

Perhaps add some images like http://www.hisparc.nl/hisparc-data/
Do we also link to subpages of jSparc?

We now have multiple 'link'-pages. Perhaps some need to be consilidated..
http://docs.hisparc.nl/
http://data.hisparc.nl/media/jsparc/
http://www.hisparc.nl/hisparc-data/
http://www.hisparc.nl/downloads/software/
(todo) http://data.hisparc.nl/