Avoid the word "mutate" while explaining const

Author: jpersson

README.md

@@ -89,7 +89,7 @@ Other Style Guides
 
   - [2.1](#2.1) <a name='2.1'></a> Use `const` for all of your references; avoid using `var`.
 
-  > Why? This ensures that you can't reassign your references (mutation), which can lead to bugs and difficult to comprehend code.
+  > Why? This ensures that you can't reassign your references, which can lead to bugs and difficult to comprehend code.
 
     ```javascript
     // bad
@@ -101,7 +101,7 @@ Other Style Guides
     const b = 2;
     ```
 
-  - [2.2](#2.2) <a name='2.2'></a> If you must mutate references, use `let` instead of `var`.
+  - [2.2](#2.2) <a name='2.2'></a> If you must reassign references, use `let` instead of `var`.
 
   > Why? `let` is block-scoped rather than function-scoped like `var`.