Pass index to T.$ function calls

[mikeselander-1p]

When using T.$() within a React context, each applied replacement requires a React key in the replaced react tag, or a key error will throw. This is easy enough to fix in a a simple string, but if you are replacing multiple spots in the same string with a single replacement, you'll end up with key issues regardless.

Instead of the following:

T.$<ReactNode>(
	"Some text <bold>that should be be bolded</bold> with more text that is also <bold>emphasized</bold>",
	{
		bold: (text) => (
			<strong key="i-will-be-duplicate">{text}</strong>
		),
	},
)

getting something like:

T.$<ReactNode>(
	"Some text <bold>that should be be bolded</bold> with more text that is also <bold>emphasized</bold>",
	{
		bold: (text, index) => (
			<strong key={`no-duplicate-${index}`}>{text}</strong>
		),
	},
)