Expand menu_arguments

[adityam]

This patch expands the options specified in menu_arguments. This allows one to say:

    "menu_arguments": [
        "-dmenu",
        "-i",
        "-dpi",
        "$ROFI_DPI"
    ],

where $ROFI_DPI is a shell variable (and thereby open rofi with different DPIs on different machines).

[MarkHedleyJones]

Thanks for your contribution! The changes look good. Are you able to manually increment the the version string from 1.2.4 to 1.3.0?
You can find it in pyproject.toml

[adityam]

Thanks. I have updated the version string in pyproject.toml.