added information about the opencorpora.org dictionary into the documentation
added information about the opencorpora.org dictionary into the documentation

mathtexts/RussianDependencyParser,maslenni/RussianDependencyParser,maslenni/RussianDependencyParser,mathtexts/RussianDependencyParser,maslenni/RussianDependencyParser,mathtexts/RussianDependencyParser