Add small improvements to the small improvements post.

content/blog/04_compiler_improvements.md

@@ -69,7 +69,7 @@ but we don't need indentation, or recursion:
 {{< codelines "C++" "compiler/04/ast.cpp" 116 121 >}}
 
 Let's print the bodies of each function we receive from the parser:
-{{< codelines "C++" "compiler/04/main.cpp" 35 50 >}}
+{{< codelines "C++" "compiler/04/main.cpp" 44 53 >}}
 
 ### Printing Types
 Types are another thing that we want to be able to inspect, so let's
@@ -83,11 +83,13 @@ The implementation is simple enough:
 
 Let's also print out the types we infer. We'll make it a separate loop
 in the `typecheck_program` function, because it's mostly just
-for debugging purposes.
+for debugging purposes:
+{{< codelines "C++" "compiler/04/main.cpp" 34 38 >}}
 
 ### Fixing Bugs
 We actually discover not one, but two bugs in our implementation thanks
-to this output. Observe the output for `works3.txt`:
+to the output we get from printing trees and types.
+Observe the output for `works3.txt`:
 ```
 length l:
   CASE:
@@ -127,7 +129,8 @@ We replace the fragment with the proper reverse iteration:
 
 
 ### Setting up CMake
-This would be extremely easy if not for Flex and Bison. We start with the usual:
+We will set up CMake as our build system. This would be extremely easy
+if not for Flex and Bison, but it's not hard either way. We start with the usual:
 {{< codelines "CMake" "compiler/04/CMakeLists.txt" 1 2 >}}
 
 Next, we want to set up Flex and Bison. CMake provides two commands for this: