Fix word mix up

Author: iluuu1994

docs/source/introduction/high-level-overview.rst

@@ -182,9 +182,9 @@ file, which contains custom DSL that is expanded by ``Zend/zend_vm_gen.php`` to
 
 Let's step through the opcodes form the example above:
 
--  We start at the top, i.e. ``JMPZ``. If its first instruction contains a "falsy" value, it will
-   jump to the instruction encoded in its second operand. If it is truthy, it will simply
-   fall-through to the next operand.
+-  We start at the top, i.e. ``JMPZ``. If its first operand contains a "falsy" value, it will jump
+   to the instruction encoded in its second operand. If it is truthy, it will simply fall-through to
+   the next instruction.
 
 -  The ``ECHO`` instruction prints its first operand.