fix broken links

CONTRIBUTING.md

@@ -131,7 +131,7 @@ gtest-type-util.h in the same directory.
 You don't need to worry about regenerating the source files unless you need to
 modify them. You would then modify the corresponding `.pump` files and run the
 '[pump.py](googletest/scripts/pump.py)' generator script. See the
-[Pump Manual](googletest/docs/PumpManual.md).
+[Pump Manual](googletest/docs/pump_manual.md).
 
 ## Developing Google Mock
 

googlemock/scripts/fuse_gmock_files.py

@@ -55,7 +55,7 @@ EXAMPLES
 This tool is experimental.  In particular, it assumes that there is no
 conditional inclusion of Google Mock or Google Test headers.  Please
 report any problems to googlemock@googlegroups.com.  You can read
-https://github.com/google/googletest/blob/master/googlemock/docs/CookBook.md for more
+https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md for more
 information.
 """