Incorporate suggestions from Kyle.

Co-authored-by: Kyle Murray <krilnon@users.noreply.github.com>

Author: amartini51

Sources/TSPL/TSPL.docc/LanguageGuide/Extensions.md

@@ -2,7 +2,7 @@
 
 # Extensions
 
-Add functionality to an existing data type.
+Add functionality to an existing type.
 
 *Extensions* add new functionality to an existing
 class, structure, enumeration, or protocol type.

Sources/TSPL/TSPL.docc/LanguageGuide/Initialization.md

@@ -2,7 +2,7 @@
 
 # Initialization
 
-Set the initial values for a type's stored properties.
+Set the initial values for a type's stored properties and perform one-time setup.
 
 *Initialization* is the process of preparing an instance of
 a class, structure, or enumeration for use.