Bump version to 0.3.1.1, updated the README a bit
Bump version to 0.3.1.1, updated the README a bit

votti/PyLaTeX,jendas1/PyLaTeX,jendas1/PyLaTeX,bjodah/PyLaTeX,bjodah/PyLaTeX,JelteF/PyLaTeX,sebastianhaas/PyLaTeX,sebastianhaas/PyLaTeX,ovaskevich/PyLaTeX,JelteF/PyLaTeX,ovaskevich/PyLaTeX,votti/PyLaTeX