Change ordering of jszip and epub.js

JSZip must be loaded before Epub JS or Epub JS will return a promise that never completes, without an error message. The docs present these dependencies in opposite order, which trips up initial setup.

Closes futurepress#1167
Closes futurepress#1248

README.md

@@ -20,16 +20,16 @@ More specifically, the EPUB schema standardizes the table of contents, provides
 
 ## Getting Started
 
-Get the minified code from the build folder:
+If using archived `.epub` files include JSZip (this must precede inclusion of epub.js):
 
 ```html
-<script src="../dist/epub.min.js"></script>
+<script src="https://cdnjs.cloudflare.com/ajax/libs/jszip/3.1.5/jszip.min.js"></script>
 ```
 
-If using archived `.epub` files include JSZip:
+Get the minified code from the build folder:
 
 ```html
-<script src="https://cdnjs.cloudflare.com/ajax/libs/jszip/3.1.5/jszip.min.js"></script>
+<script src="../dist/epub.min.js"></script>
 ```
 
 Set up a element to render to: