Add vendor

Specifically because I want to modify a dependency

vendor/github.com/charmbracelet/x/ansi/util.go

@@ -0,0 +1,29 @@
+package ansi
+
+import (
+	"fmt"
+	"image/color"
+)
+
+// colorToHexString returns a hex string representation of a color.
+func colorToHexString(c color.Color) string {
+	if c == nil {
+		return ""
+	}
+	shift := func(v uint32) uint32 {
+		if v > 0xff {
+			return v >> 8
+		}
+		return v
+	}
+	r, g, b, _ := c.RGBA()
+	r, g, b = shift(r), shift(g), shift(b)
+	return fmt.Sprintf("#%02x%02x%02x", r, g, b)
+}
+
+// rgbToHex converts red, green, and blue values to a hexadecimal value.
+//
+//	hex := rgbToHex(0, 0, 255) // 0x0000FF
+func rgbToHex(r, g, b uint32) uint32 {
+	return r<<16 + g<<8 + b
+}