Fix minor inconsistencies

- Remove whitespace in header of chapter 7
- Correct header levels in chapter 10
- Correct main header in chapter 11

ch07.md

@@ -1,4 +1,4 @@
-# Chapter 07:  Hindley-Milner and Me
+# Chapter 07: Hindley-Milner and Me
 
 ## What's your type?
 If you're new to the functional world, it won't be long before you find yourself knee deep in type signatures. Types are the meta language that enables people from all different backgrounds to communicate succinctly and effectively. For the most part, they're written with a system called "Hindley-Milner", which we'll be examining together in this chapter.

ch10.md

@@ -191,7 +191,7 @@ map(add, Right(2)).ap(Right(3));
 
 It's helpful to know that `<$>` is `map` (aka `fmap`) and `<*>` is just `ap`. This allows for a more natural function application style and can help remove some parenthesis.
 
-# Free can openers
+## Free can openers
 <img src="images/canopener.jpg" alt="http://breannabeckmeyer.com/drawing.html" />
 
 We haven't spoken much about derived functions. Seeing as all of these interfaces are built off of each other and obey a set of laws, we can define some weaker interfaces in terms of the stronger ones.
@@ -233,7 +233,7 @@ Monads have the unique ability to sequence computation, assign variables, and ha
 
 Now, on to the legalities ...
 
-# Laws
+## Laws
 
 Like the other mathematical constructs we've explored, applicative functors hold some useful properties for us to rely on in our daily code. First off, you should know that applicatives are "closed under composition", meaning `ap` will never change container types on us (yet another reason to favor over monads). That's not to say we cannot have multiple different effects - we can stack our types knowing that they will remain the same during the entirety of our application.
 

ch11.md

@@ -1,4 +1,4 @@
-# Ch11: Transform Again, Naturally
+# Chapter 11: Transform Again, Naturally
 
 We are about to discuss *natural transformations* in the context of practical utility in every day code. It just so happens they are a pillar of category theory and absolutely indispensable when applying mathematics to reason about and refactor our code. As such, I believe it is my duty to inform you about the lamentable injustice you are about to witness undoubtedly due to my limited scope. Let's begin.