Add and compare literature fragments

[dominiquesydow]

Add data for all literature fragments and set up stand-alone notebook to compare them to our fragments (so far mainly done visually by hand, documented off-line).

First steps are in fragment_analysis.ipynb:

Yang et al. publication add DOI/link; and what is the result of the analysis (we should have found it?)
Initially, I thought we do not have those large fragments in our library, but turns out we have. To make this part more meaningful, I should add all their fragments and check if we have them.

[dominiquesydow]

Moved these first steps to fragment_analysis_literature.

[dominiquesydow]

Notebook 2_4_fragment_analysis_literature.ipynb moved to branch fragment_analysis_literature (will not be included in first release).

[dominiquesydow]

This analysis will remain by hand. Closing issue.