Update 100_preReqs.ngdoc

Fixes a spelling mistake in the docs.

Author: JLLeitschuh

misc/tutorial/100_preReqs.ngdoc

@@ -21,6 +21,6 @@ Current list of tested browsers: <a href='https://saucelabs.com/u/nggrid' target
 
 Note that IE9 compatibility is marginal - the base functions all work but performance is poor in some cases, 
 and some behaviour is not as desired.  We have limited ability to control some of this, but have decided to retain IE9 
-in the supported list due to the small number of organisations for whom this is critical.  If using on IE9 we 
+in the supported list due to the small number of organizations for whom this is critical.  If using on IE9 we 
 recommend testing your specific use cases to verify all your desired functions work adequately.