Rename to general and anselm

@jir13 @prd001 přejmenováno, prosím o kontrolu

git mv docs.it4i/get-started-with-it4innovations/ docs.it4i/general
git mv docs.it4i/anselm-cluster-documentation/ docs.it4i/anselm
find docs.it4i/ -name '*.md' -exec sed -i  's/get-started-with-it4innovations/general/g' {} +
find docs.it4i/ -name '*.md' -exec sed -i  's/anselm-cluster-documentation/anselm/g' {} +
sed -i  's/anselm-cluster-documentation/anselm/g' mkdocs.yml 
sed -i  's/get-started-with-it4innovations/general/g' mkdocs.yml