Document ISA-Tab patterns

[proccaserra]

Following discussions with NASA Genelab, provide more information about

• valid ISA-Tab layouts
• antipatterns: what things break ISA-Tab
• create jupyter notebook showing these patterns
• create notebook showing chains of data transformation (valid or not with the ISA-API)
• create notebook showing FactorValues on assay tables (not just on Study Table)
• create notebook showing FactorValues in other location than packed at the right of the table

[proccaserra]

closing now, addressed by:

• Added missing notebooks from https://github.com/ISA-tools/isa-api/pull/585 #601
• [x ] jupyter notebook testing and revisions/corrections #603