Support running code before compiling the main file

[PHPirates]

Fix #3040

Summary of additions and changes

• Allow running LaTeX before running the main file. There are certainly nicer ways to do this but I want to save that for the new run config

How to test this pull request

\documentclass{article}
\usepackage{etoolbox}

\providecommand{\waarde}{true}
\newbool{binair}
\setbool{binair}{\waarde}

\begin{document}
    \ifbool{binair}{waar}{onwaar}
\end{document}

then put \newcommand{\waarde}{false} in run config

• Updated the documentation, or no update necessary
• Test on Windows
• Fix latexmk
• re-add 'compiler arguments' label