Fix inline equation example in README.adoc
Fix inline equation example in README.adoc

The inline equation in the Diophantine equation theorem environment is interpreted as a literal string rather than an equation. Removing the back slashes fixes this. I am not sure if this is a bug with the documentation or the program.
asciidoctor/asciidoctor-latex,asciidoctor/asciidoctor-latex,asciidoctor/asciidoctor-latex