Fix typo in Belt.Option.flatMap example

Author: persianturtle

docs/api/Belt.Option.html

@@ -195,7 +195,7 @@ <h1>Module <a href="type_Belt.Option.html">Belt.Option</a></h1>
 
                     </div>
                      <div class="examples">
-                    <pre class="example"> <pre class="codepre"><code class="code">    let f (x : float =
+                    <pre class="example"> <pre class="codepre"><code class="code">    let f (x : float) =
         if x &gt;= 0.0 then
           Some (sqrt x)
         else