Template and docs MS Excel example

[tbrittoborges]

We would like to use MS Excel as data input so collaborators can fill in their Study, Investigation and Assay metadata.

I see there are issues (#91 #68) related to using MS Excel, but I don't see a template or documentation on this. Would you kindly provide a template and some documentation and explain how do you use it with altamisa?

We are considering using MAGE-TAB templates, but there are ambiguities between MAGE-TAB and ISA model which are not trivial to sort out. So the ISA as MS Excel spreadsheet would be ideal.