Include `rnote-cli` utility command into the package

rnote repositiory offers an utility command rnote-cli which can convert rnote file to SVGs from the command line. It would be usefull if this command was also included into the package.

I'm not familier with meson build system, but it looks like its just need to add --cli option. https://github.com/flxzt/rnote/blob/f0487ef153139cd5fe44438af50dcbf9182be633/meson.build#L23