various updates and revisions

v0.7.4

adapt broken links

simpler interface

simplify get_concept(). Search parameters are now not provided via a table anymore but as a combination of column name and value to search for in that column. They can also be provided as a string representing a query that would be used in dplyr::filter(), where several search conditions can be combined arbitrarily.

fuzzy matching wip

This release includes getters to access classes, concepts and sources. It allows editing matches, is also supported by fuzzy matching and improves usability quite a bit.

intial release

initial release