Fix slash direction for linux path

Update direction of the slash, for linux path, after @hanno-arm comments
diff --git a/git_hooks/README.md b/git_hooks/README.md
index f78df99..400d63e 100644
--- a/git_hooks/README.md
+++ b/git_hooks/README.md
@@ -8,7 +8,7 @@
 
 Example:
 
-Execute the following command to create a link on linux from the mbed TLS `.git\hooks` directory:  
+Execute the following command to create a link on linux from the mbed TLS `.git/hooks` directory:  
 `ln -s ../../git_hooks/pre-push pre-push`
 
 **Note: Currently the mbed TLS git hooks work only on a GNU platform. If using a non-GNU platform, don't enable these hooks!**