Fix backslashes in README.md (#29)

diff --git a/README.md b/README.md
index 5803470..ee346a6 100644
--- a/README.md
+++ b/README.md
@@ -97,8 +97,8 @@
 We believe this library handles most of the corner cases of Windows paths
 (POSIX paths are generally pretty straightforward):
 
- *  It understands that *both* "/" and "\" are valid path separators, not just
-    "\".
+ *  It understands that *both* "/" and "\\" are valid path separators, not just
+    "\\".
 
  *  It can accurately tell if a path is absolute based on drive-letters or UNC
     prefix.