Add initial documentation around CORS usage

Author: timothycrosley

FAQ.md

@@ -6,13 +6,13 @@ For more examples, check out Hug's [documentation](https://github.com/timothycro
 
 Q: *Can I use Hug with a web framework -- Django for example?*
 
-A: You can use Hug alongside Django or the web framework of your choice, but it does have drawbacks. You would need to run hug on a separate, hug-exclusive server. You can also [mount Hug as a WSGI app](https://pythonhosted.org/django-wsgi/embedded-apps.html), embedded within your normal Django app. 
+A: You can use Hug alongside Django or the web framework of your choice, but it does have drawbacks. You would need to run hug on a separate, hug-exclusive server. You can also [mount Hug as a WSGI app](https://pythonhosted.org/django-wsgi/embedded-apps.html), embedded within your normal Django app.
 
 Q: *Is Hug compatabile with Python 2?*
 
-A: Python 2 is not supported by Hug. However, if you need to account for backwards compatability, there are workarounds. For example, you can wrap the decorators: 
+A: Python 2 is not supported by Hug. However, if you need to account for backwards compatability, there are workarounds. For example, you can wrap the decorators:
 
-```Python 
+```Python
 def my_get_fn(func, *args, **kwargs):
     if 'hug' in globals():
         return hug.get(func, *args, **kwargs)
@@ -29,7 +29,7 @@ Q:  *How can I serve static files from a directory using Hug?*
 
 A: For a static HTML page, you can just set the proper output format as: `output=hug.output_format.html`. To see other examples, check out the [html_serve](https://github.com/timothycrosley/hug/blob/develop/examples/html_serve.py) example, the [image_serve](https://github.com/timothycrosley/hug/blob/develop/examples/image_serve.py) example, and the more general [static_serve](https://github.com/timothycrosley/hug/blob/develop/examples/static_serve.py) example within `hug/examples`.
 
-Most basic examples will use a format that looks something like this: 
+Most basic examples will use a format that looks something like this:
 
 ```Python
 @hug.static('/static')
@@ -50,15 +50,15 @@ A: You can access a list of your routes by using the routes object on the HTTP A
 
 `__hug_wsgi__.http.routes`
 
-It will return to you a structure of "base_url -> url -> HTTP method -> Version -> Python Handler". Therefore, for example, if you have no base_url set and you want to see the list of all URLS, you could run: 
+It will return to you a structure of "base_url -> url -> HTTP method -> Version -> Python Handler". Therefore, for example, if you have no base_url set and you want to see the list of all URLS, you could run:
 
 `__hug_wsgi__.http.routes[''].keys()`
 
 Q: *How can I configure a unique 404 route?*
 
 A: By default, Hug will call `documentation_404()` if no HTTP route is found. However, if you want to configure other options (such as routing to a directiory, or routing everything else to a landing page) you can use the `@hug.sink('/')` decorator to create a "catch-all" route:
 
-```Python 
+```Python
 import hug
 
 @hug.sink('/all')
@@ -67,3 +67,23 @@ def my_sink(request):
 ```
 
 For more information, check out the ROUTING.md file within the `hug/documentation` directory.
+
+Q: *How can I enable CORS*
+
+A: There are many solutions depending on the specifics of your application.
+For most applications, you can use the included cors middleware:
+
+```
+import hug
+
+api = hug.API(__name__)
+api.http.add_middleware(hug.middleware.CORSMiddleware(api, max_age=10))
+
+
+@hug.get("/demo")
+def get_demo():
+    return {"result": "Hello World"}
+```
+For cases that are more complex then the middleware handles
+
+[This comment]([https://github.com/hugapi/hug/issues/114#issuecomment-342493165]) (and the discussion around it) give a good starting off point.