update docs for array access to return an option

Author: jderochervlk

pages/docs/manual/latest/array-and-list.mdx

@@ -25,27 +25,48 @@ ReScript arrays' items must have the same type, i.e. homogeneous.
 
 ### Usage
 
-Access & update an array item like so:
+Accessing items in an array will return an `option` and can be done like so:
 
 <CodeTab labels={["ReScript", "JS Output"]}>
 
 ```res example
 let myArray = ["hello", "world", "how are you"]
 
-let firstItem = myArray[0] // "hello"
+let firstItem = myArray[0] // Some("hello")
 
-myArray[0] = "hey" // now ["hey", "world", "how are you"]
-
-myArray->Array.push("bye")
+let tenthItem = myArray->Array.get(10) // None
 ```
 ```js
 var myArray = ["hello", "world", "how are you"];
 
 var firstItem = myArray[0];
 
+var tenthItem = myArray[10];
+```
+
+</CodeTab>
+
+Items in an array can be updated by assigning a value to an index or using a function:
+
+<CodeTab labels={["ReScript", "JS Output"]}>
+
+```res example
+let myArray = ["hello", "world", "how are you"]
+
+myArray[0] = "hey" // now ["hey", "world", "how are you"]
+
+myArray->Array.push("?") //  ["hey", "world", "how are you", "?"]
+
+myArray->Array.set(0, "bye") //  ["bye", "world", "how are you", "?"]
+```
+```js
+var myArray = ["hello", "world", "how are you"];
+
 myArray[0] = "hey";
 
-var pushedValue = myArray.push("bye");
+myArray.push("?");
+
+myArray[0] = "bye";
 ```
 
 </CodeTab>