fix typos

Author: giuseppeg

README.md

@@ -380,9 +380,9 @@ By default, the `mini-css-extract-plugin` appends styles (`<link>` elements) to
 
 However in some circumstances it might be necessary to have finer control over the append target or even delay `link` elements instertion. For example this is the case when you asynchronously load styles for an application that runs inside of an iframe. In such cases `insert` can be configured to be a function or a custom selector.
 
-If you target an [iframe](https://developer.mozilla.org/en-US/docs/Web/API/HTMLIFrameElement) make sure that the parent document can has sufficient access rights to reach into the frame document and append elements to it.
+If you target an [iframe](https://developer.mozilla.org/en-US/docs/Web/API/HTMLIFrameElement) make sure that the parent document has sufficient access rights to reach into the frame document and append elements to it.
 
-#### `String`
+#### `insert` as a string
 
 Allows to configure a [CSS selector](https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelector) that will be used to find the element where to append the styles (`link` elements).
 
@@ -394,11 +394,12 @@ new MiniCssExtractPlugin({
 
 A new `<link>` element will be appended to the `#my-container` element.
 
-#### `Function`
+#### `insert` as a function
 
 Allows to override default behavior and insert styles at any position.
 
 > ⚠ Do not forget that this code will run in the browser alongside your application. Since not all browsers support latest ECMA features like `let`, `const`, `arrow function expression` and etc we recommend you to use only ECMA 5 features and syntax.
+
 > ⚠ The `insert` function is serialized to string and passed to the plugin. This means that it won't have access to the scope of the webpack configuration module.
 
 ```js