fix minor spacing issue

index.Rmd

@@ -35,8 +35,7 @@ You can read the web version of the book on this site. Click a section in the ta
 on the left side of the page to navigate to it. If you are on a mobile device,
 you may need to open the table of contents first by clicking the menu button on 
 the top left of the page. You can purchase a PDF or print copy of the book 
-on the [CRC Press website](https://www.routledge.com/Data-Science-A-First-Introduction/Timbers-Campbell-Lee/p/book/9780367524685)
-or on [Amazon](https://www.amazon.com/Data-Science-First-Introduction-Chapman/dp/0367532174).
+on the [CRC Press website](https://www.routledge.com/Data-Science-A-First-Introduction/Timbers-Campbell-Lee/p/book/9780367524685) or on [Amazon](https://www.amazon.com/Data-Science-First-Introduction-Chapman/dp/0367532174).
 
 For the python version of the textbook, visit [https://python.datasciencebook.ca](https://python.datasciencebook.ca).