PVector tutorial: add missing starting square bracket

Author: babaissarkar

content/tutorials/text/pvector/index.mdx

@@ -193,7 +193,7 @@ In an ideal world, we would just be able to rewrite the above to be:
   location = location + velocity;
 ```
 
-However, in Processing, the addition operator '+' is reserved for primitive values (integers, floats, etc.) only. Processing doesn't know how to add two **PVector**](http://processing.org/reference/PVector.html) objects together any more than it knows how to add two PFont objects or PImage objects. Fortunately for us, the [**PVector**](http://processing.org/reference/PVector.html) class is implemented with functions for common mathematical operations.
+However, in Processing, the addition operator '+' is reserved for primitive values (integers, floats, etc.) only. Processing doesn't know how to add two [**PVector**](http://processing.org/reference/PVector.html) objects together any more than it knows how to add two PFont objects or PImage objects. Fortunately for us, the [**PVector**](http://processing.org/reference/PVector.html) class is implemented with functions for common mathematical operations.
 
 ## Vectors: Addition