added VSG (a verilog formatter by jeremiah-c-leary/vhdl-style-guide)

[superzanti]

Describe your changes

I added VSG which is a VHDL formatter.

Issue ticket number and link

Checklist before requesting a review

• I have successfully tested installation of the package.
• I have successfully tested the package after installation.
  

Simply installing VSG from mason and using the following lua for conform.nvim (which already supports VSG) provides full support:

        require("conform").setup({
            formatters_by_ft = {
                vhdl = { "vsg" },
            },
        })

Screenshots

[williamboman]

Thanks!