Speaker notes for Method example (#203)

* Speaker notes for Method example

* Update example.md

Author: cchiw

src/methods/example.md

@@ -39,3 +39,14 @@ fn main() {
     race.finish();
 }
 ```
+
+<details>
+    
+Key Points:
+* All four methods here use a different method receiver.
+  * You can point out how that changes what the function can do with the variable values and if/how it can be used again in `main`.
+  * You can showcase the error that appears when trying to call `finish` twice.
+* Note, that although the method receivers are different, the non-static functions are called the same way in the main body. Rust enables automatic referencing and dereferencing when calling methods. Rust automatically adds in the `&`, `*`, `muts` so that that object matches the method signature.
+* You might point out that `print_laps` is using a vector that is iterated over. We describe vectors in more detail in the afternoon. 
+
+</details>