adding a bit more to the README

README.md

@@ -1,12 +1,18 @@
 # Essentials of Compilation
 
-A book about compiling Racket to x86-64 assembly
+This is a book about compiling a subset of Racket to x86-64 assembly code.
 
 **Generating the book**
 
-To generate the book (`book.pdf`), run the `make` command (assuming you have a full install of TeX Live).
+To generate the book (`build/book.pdf`), run the `make` command (assuming
+you have a full install of TeX Live).
 
 **Related resources**
 
 * [IU Compiler Course Webpage](https://iucompilercourse.github.io/IU-P423-P523-E313-E513-Fall-2020/)
 * [Public Student Support Code](https://github.com/IUCompilerCourse/public-student-support-code)
+
+If you are an instructor, you may also request access to the reference
+implementation of the compiler and the full test suite.
+
+* [Instructor Solution](https://github.com/IUCompilerCourse/course-compiler)