Update README.md

Cleared up some language on the answer to question 13.24.

ch13/README.md

@@ -163,7 +163,7 @@ Check 13.22.
 ## Exercise 13.24:
 >What would happen if the version of `HasPtr` in this section didn’t define a destructor? What if `HasPtr` didn’t define the copy constructor?
 
-If `HasPtr` didn't define a destructor, memory leak will happened. If `HasPtr` didn't define the copy constructor, when assignment happened, just points copied, the string which `ps` points haven't been copied.
+If `HasPtr` didn't define a destructor, a memory leak would occur, compiler synthesized destructor does not manage dynamic memory. If `HasPtr` didn't define the copy constructor, we would get pointer-like copy behaviour. The ps pointer would be copied to the left hand side, but ps in the lhs and the rhs would still point to the same string on the heap. 
 
 ## Exercise 13.25:
 >Assume we want to define a version of `StrBlob` that acts like a value. Also assume that we want to continue to use a shared_ptr so that our `StrBlobPtr` class can still use a weak_ptr to the vector. Your revised class will need a copy constructor and copy-assignment operator but will not need a destructor. Explain what the copy constructor and copy-assignment operators must do. Explain why the class does not need a destructor.