xiantang/darcula-dark theme support

[DangGwanHou]

Wish can support this theme: https://github.com/xiantang/darcula-dark.nvim
For beginners and friends who are used to the highlight of JetBrains product series and then switch to neovim, it will be very hoped that
will integrate this theme.

[xiantang]

im the author of https://github.com/xiantang/darcula-dark.nvim, thank you for recommend this theme @DangGwanHou