New option `default-sentence-range`

[muzimuzhi]

To get screenshots of proper size, sometimes what I want is just 2 to 3 lines of dummy text each time, while the first several paragraphs in lipsum text are just too long. Instead of specifying the second optional arguments all the time, an option specifying the default sentence range would be convenient.

\documentclass{article}
\usepackage{lipsum}

\newtheorem{thm}{Theorem}

\begin{document}
\lipsum[1][1-3]
\begin{thm}
  \lipsum[2][1-3]
\end{thm}
\lipsum[3][1-3]
\end{document}