Add Go format string coloring

[Nico-Mayer]

Is your feature request related to a problem? Please describe.
While working with Go, I observed that all Material themes lack string format coloring. For instance, there is no distinct highlighting for string formatting in expressions like fmt.Printf("Value%d", value).

Describe the solution you'd like
I would appreciate a solution akin to the default Visual Studio Code theme, where all values prefixed with '%' are highlighted.

Additional context
I believe implementing this should be relatively straightforward, given that the default theme already incorporates such features. I would greatly appreciate seeing this enhancement in future updates. I genuinely love the theme – keep up the excellent work! :)

[equinusocio]

Hello, I guess this highlight depends on semantic color highlight. Have you enabled it? If yes, can you post a valid (without errors) code so we can test it?

If not, try enabling it to check if something changes. If not post a valid code here to test against.

[Nico-Mayer]

I have it enabled in my global setting.json:

Example with Material Theme Deepforest Hight Contrast:

Example with VS Code default Dark+ Theme:

edit:

Test Code:

package main

import "fmt"

func main() {
	firstDigit := 1
	lastDigit := 0

	fmt.Printf("First Digit: %d\n", firstDigit)
	fmt.Printf("Last Digit: %d\n", lastDigit)
}

[equinusocio]

We added support for constant.placeholder tokens in every language, not only go. The color will be red.

Release on the way.