Auto merge of rust-lang#9106 - usefulmove:master, r=flip1995

corrected README.md book link

This change corrects the book link on the Clippy Book README.md.

changelog: none

Author: bors

book/README.md

@@ -1,4 +1,4 @@
 # Clippy Book
 
 This is the source for the Clippy Book. See the
-[book](src/infrastructure/book.md) for more information.
+[book](src/development/infrastructure/book.md) for more information.