CH16 reference to static main.css missing quotes

[reybango]

Adding this here for addition to the addendum and updates to the 2ed copy of the book.

In the book, the code being mentioned on pg 186 says to define the static resource like this:

<link rel="stylesheet" href="{{static /css/main.css}}">

It's missing single quotes around the file path and file name like this:

<link rel="stylesheet" href="{{static '/css/main.css'}}">

Without them it'll not include the stylesheet into the page.