Correct capitalization

Author: mattcone

manuscript/chapter1.md

@@ -48,7 +48,7 @@ The short answer is that you need a *Markdown application* capable of processing
 
 Markdown applications use something called a *Markdown processor* (also commonly referred to as a "parser" or an "implementation") to take the Markdown-formatted text and output it to HTML format. At that point, your document can be viewed in a web browser or combined with a style sheet and printed. You can see a visual representation of this process below.
 
-I> The Markdown application and processor are two separate components. For the sake of brevity, I've combined them into one element ("Markdown App") in the figure below.
+I> The Markdown application and processor are two separate components. For the sake of brevity, I've combined them into one element ("Markdown app") in the figure below.
 
 {width=100%}
 ![This is a visual overview of the Markdown process.](images/process.png)