Add some better file comments

compile.c

@@ -1,4 +1,4 @@
-
+// Compilation logic
 #include <ctype.h>
 #include <gc/cord.h>
 #include <gc.h>

enums.c

@@ -1,4 +1,4 @@
-
+// Logic for compiling tagged unions (enums)
 #include <ctype.h>
 #include <gc/cord.h>
 #include <gc.h>

environment.c

@@ -1,4 +1,5 @@
-
+// Logic for the environmental context information during compilation
+// (variable bindings, code sections, etc.)
 #include <stdlib.h>
 #include <signal.h>
 

parse.c

@@ -1,4 +1,4 @@
-// Parse code using recursive descent
+// Recursive descent parser for parsing code
 #include <ctype.h>
 #include <gc.h>
 #include <libgen.h>

structs.c

@@ -1,4 +1,4 @@
-
+// Logic for compiling new struct types defined in code
 #include <ctype.h>
 #include <gc/cord.h>
 #include <gc.h>

tomo.c

@@ -1,3 +1,4 @@
+// The main program that runs compilation
 #include <stdio.h>
 #include <stdlib.h>
 #include <gc.h>