internal/rosa: key-value type

This type is used very frequently. The new type is much easier to type and can receive helper methods eventually if needed.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/etc.go

@@ -25,7 +25,7 @@ func (a cureEtc) Cure(t *pkg.FContext) (err error) {
 	if err = os.MkdirAll(etc.String(), 0700); err != nil {
 		return
 	}
-	for _, f := range [][2]string{
+	for _, f := range []KV{
 		{"hosts", "127.0.0.1 localhost cure cure-net\n"},
 		{"passwd", `root:x:0:0:System administrator:/proc/nonexistent:/bin/sh
 cure:x:1023:1023:Cure:/usr/src:/bin/sh