Typos and addition to Acks in preface.rst

preface.rst

@@ -140,10 +140,10 @@ Code Examples
 
 Since the first edition of this book, we have used code examples to
 illustrate how various protocols and algorithms might be
-implemented. Originally, the code came from the $x$-kernel, a
+implemented. Originally, the code came from the *x*-kernel, a
 framework for protocol implementation and research developed in the
 1990s, and you could compile and run every code fragment in the
-book. As the $x$-kernel code is no longer maintained, we no longer
+book. As the *x*-kernel code is no longer maintained, we no longer
 check that all the code in the book compiles or runs. At this point
 the code should only be used as a guide to assist the reader in
 understanding the topic at hand.
@@ -206,6 +206,7 @@ contributions and bug fixes:
    -  Yihao Wang (y1hao)
    -  Charles Reiss (charlesreiss)
    -  Karanveer B. (KaranveerB)
+   -  Meek Msaki (mmsaki)
 
 Finally, we would like to thank the following reviewers for their many
 helpful comments and suggestions. Their impact was significant.