Store manual annotations done in Shiny in a more machine-readable format

[ChristophLeonhardt]

Currently, the manual additions are logged in a txt file essentially containing something akin to a whitespace separated tabular representation of s-attributes used for linking, variables added manually / fuzzily and a caption providing the attribute name, the package version and the date.

To be fully reproducible, repeated linkage procedures should be able to use an output like that as the input it is run the next time, instead of having to select and add values manually everytime the linkage is done.

Aside from implementing this, this would require a more standardized output format.