Add import section title support to core isort code
Add import section title support to core isort code

wimglenn/isort,graingert/isort,jamesbroadhead/isort,adamchainz/isort,adamchainz/isort,graingert/isort,PyCQA/isort,leepa/isort,levic/isort,PyCQA/isort,AbsoluteMSTR/isort,gforcada/isort,levic/isort,jmullan/isort,pahko/isort,tomviner/isort,wimglenn/isort,gforcada/isort,leepa/isort,jmullan/isort,pahko/isort,aequitas/isort,aequitas/isort,jamesbroadhead/isort,AbsoluteMSTR/isort,tomviner/isort