Set double spacing and line numbers when converting from Markdown to PDF with pandoc

Question

I am using markdown & pandoc for scientific writing, I know I can change margins of the final pdf using

Set margin size when converting from Markdown to PDF with pa

Answer 1

There is maybe an easy way: generate a file with the packages we need

 \usepackage{setspace}
 \doublespacing
 \usepackage[vmargin=1in,hmargin=1in]{geometry}
 \usepackage{lineno}
 \linenumbers

I named it options.sty. And use the -H FILE option that includes the content of the FILE at the end of the preamble. (as used in https://github.com/karthikram/smb_git)

 pandoc -H options.sty --bibliography mypaper.bib mypaper.md -o mypaper.pdf 

The advantage is that we don't need to edit the template. To add linenumbers, change margins, and set spacing it works.