[docs] Update Readme
[docs] Update Readme

* added DIMSpan paper
smee/gradoop,p3et/gradoop,galpha/gradoop,p3et/gradoop,rostam/gradoop,s1ck/gradoop,dbs-leipzig/gradoop,niklasteichmann/gradoop,galpha/gradoop,rostam/gradoop,smee/gradoop,niklasteichmann/gradoop,s1ck/gradoop,dbs-leipzig/gradoop