Inheritance and not "inheritence"

[kielbasi]

Hi !

Thanks for the wonderful work on this very useful extension. When activating :allow-dot-graphs: on doxygenclass directives, I saw that there is a misfit in the spelling of the word "inheritance".

The concerned line is 487 of breathe/parser/compoundsuper.py.

Thanks in advance

[michaeljones]

Thank you for pointing that out. I've made a PR: https://github.com/breathe-doc/breathe/pull/914