Add module declarations to introduction chapters to please stack

Author: bryal

Physics/src/Introduction/About.lhs

@@ -39,7 +39,11 @@ The book is aimed at you who have some knowledge of
 sure you could pick it up as we go. We believe in you!
 
 If you wonder about the weird code blocks at the start of many
-chapters, they are there to declare the chapters as Haskell
+chapters,
+
+> module Introduction.About where
+
+they are there to declare the chapters as Haskell
 modules. All chapters are written in *Literate Haskell*, and can be
 used with GHC/GHCi directly as source code. Therefore, you may choose
 to read each chapter as documented source code, rather than text with

Physics/src/Introduction/GettingStarted.lhs

@@ -1,6 +1,4 @@
-
-
-
+> module Introduction.GettingStarted where
 
 What you need to dive in
 ======================================================================

Physics/src/Introduction/WhatIsADsl.lhs

@@ -1,3 +1,5 @@
+> module Introduction.WhatIsADsl where
+
 So what's a DSL?
 ======================================================================