Fix app_fs & app_os typos

Author: CrashTestJava

api/app_fs.md

@@ -1,6 +1,6 @@
 # app.fs
 
-A set of function to handle file names and the file system.
+A set of functions to handle file names and the file system.
 
 # Path & File Name Manipulation
 

api/app_os.md

@@ -1,6 +1,6 @@
 # app.os
 
-A set of function to get properties about the running Operating System
+A set of functions to get properties about the running Operating System
 platform.
 
 ## app.os.name