Typo fix

Shepherd.tex

@@ -81,7 +81,7 @@ Shepherd to my attention back in 2015. I also want to thank the OWASP Foundation
 and the OWASP chapter in Gothenburg for help with getting started with Security
 Shepherd. Thanks to the LiU IT department who was willing to set up and support
 a web application server that, contrary to all common sense and in violation of
-probablya dozen IT policies, contains all kinds of web vulnerabilities. Also
+probably a dozen IT policies, contains all kinds of web vulnerabilities. Also
 thanks to Niklas Johansson for helping me get all the lab details straight and,
 of course, prof. Jan-Åke Larsson, who gave us the go-ahead to build what is
 probably going to be a very interesting lab course.
@@ -279,7 +279,6 @@ This is the first time we have ever attempted to give a lab course that is this
 complex. We have put a lot of work into making the lab interesting and to run
 the actual server. If you have any ideas or suggestions we are all ears!
 
-
 \section{Challenges}\label{sec:challenges}
 The following challenges are required to pass the lab. The challenges we put at
 the end of the list are the hardest, so we recommend that you don't start with