Update Exercises Directory Names to Reflect Order

exercises/06_move_semantics/move_semantics6.rs

@@ -0,0 +1,28 @@
+// move_semantics6.rs
+//
+// You can't change anything except adding or removing references.
+//
+// Execute `rustlings hint move_semantics6` or use the `hint` watch subcommand
+// for a hint.
+
+// I AM NOT DONE
+
+fn main() {
+    let data = "Rust is great!".to_string();
+
+    get_char(data);
+
+    string_uppercase(&data);
+}
+
+// Should not take ownership
+fn get_char(data: String) -> char {
+    data.chars().last().unwrap()
+}
+
+// Should take ownership
+fn string_uppercase(mut data: &String) {
+    data = &data.to_uppercase();
+
+    println!("{}", data);
+}