Update terminal colors

[aarowill]

Fix terminal colors in default color scheme according to https://github.com/chriskempson/base16-xresources (and the rest of the terminal color scheme repos).
Add 256 color scheme template that doesn't make bright colors behave unexpectedly according to https://github.com/chriskempson/base16-shell.

[golf1052]

Thanks for the CR and pointing to the base16-shell repo. I've updated the standard colors to match what you had (which also matches the base16-shell repo). I however am not going to take the bright colors as they are different than what base16-shell recommends. I've pasted images below showing the difference. Also VSCode currently doesn't support theming for 256 or 24-bit colors, only 4-bit, see here, so I will not add the 256.json output either.

Your colors

Suggested colors

VSCode Dark+ colors