Update node-gyp.md

Maybe a typo

PR-URL: #226
Reviewed-By: Michael Dawson <[email protected]>

Author: kYroL01

doc/node-gyp.md

@@ -7,7 +7,7 @@ The main reason for this is that we need to link to the Node.js dependencies and
 headers correcrtly, another reason is that we need a cross platform way to build
 C++ soucre into binary for the target platform,
 
-Until now **node-gyp** is the **de-fafto** standard build tool for writing
+Until now **node-gyp** is the **de-facto** standard build tool for writing
 Node.js addons. It's based on Google's **gyp** build tool, which abstract away
 many of the tedious issues related to cross platform building.