Add vendor

Specifically because I want to modify a dependency

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

@@ -0,0 +1,8 @@
+package ansi
+
+const (
+	// SP is the space character (Char: \x20).
+	SP = 0x20
+	// DEL is the delete character (Caret: ^?, Char: \x7f).
+	DEL = 0x7F
+)