Merge pull request #3103 from tbm/typos

Fix typos in the documentation

docs/config.rst

@@ -565,7 +565,7 @@ then you must do so before calling :meth:`~flask.Config.from_object`::
     cfg = import_string('configmodule.ProductionConfig')()
     app.config.from_object(cfg)
 
-Instantiating the configutation object allows you to use ``@property`` in
+Instantiating the configuration object allows you to use ``@property`` in
 your configuration classes::
 
     class Config(object):

docs/extensions.rst

@@ -25,7 +25,7 @@ Consult each extension's documentation for installation, configuration,
 and usage instructions. Generally, extensions pull their own
 configuration from :attr:`app.config <flask.Flask.config>` and are
 passed an application instance during initialization. For example,
-an extension caled "Flask-Foo" might be used like this::
+an extension called "Flask-Foo" might be used like this::
 
     from flask_foo import Foo
 

docs/patterns/caching.rst

@@ -11,7 +11,7 @@ you actually put the result of that calculation into a cache for some
 time.
 
 Flask itself does not provide caching for you, but `Flask-Caching`_, an
-extentions for Flask does. Flask-Caching supports various backends, and it is
+extension for Flask does. Flask-Caching supports various backends, and it is
 even possible to develop your own caching backend.