feat: report skipped file updates

update.sh

@@ -8,7 +8,13 @@ update_file() {
     local A="$1"
     local B="$2"
 
-    if [ -f "$A" ] && [ -f "$B" ] && [ "$(cat "$A")" != "$(cat "$B")" ]; then
+    if [ ! -f "$B" ]; then
+        echo "File $B does not exist, skipping update."
+        printf 'Run: mkdir -p %q && cp %q %q\n' "$(dirname "$B")" "$A" "$B"
+        return
+    fi
+
+    if [ -f "$A" ] && [ "$(cat "$A")" != "$(cat "$B")" ]; then
         cp "$A" "$B"
         echo "File $B has been updated."
     fi