fix(lean_sphinx.py): add Gabriel Ebner's fix for epub
fix(lean_sphinx.py): add Gabriel Ebner's fix for epub

leanprover/logic_and_proof,avigad/logic_and_proof,leanprover/logic_and_proof,avigad/logic_and_proof,fpvandoorn/logic_and_proof,fpvandoorn/logic_and_proof,fpvandoorn/logic_and_proof,rlewis1988/logic_and_proof,avigad/logic_and_proof,leanprover/logic_and_proof,rlewis1988/logic_and_proof,rlewis1988/logic_and_proof