AUI-1394 Create tutorial for Affix

Note: the jira ticket is to create both a tutorial and examples for this
module. This commit only contains the tutorial part. The api link is not
yet on the site's api, but should be correct. The "Configuring Affix"
section needs the most work -- not clear yet if there are other options,
and if this section should be removed if there are not.
Add affix temp example
AUI-1399 Create tutorial for ColorPicker

Note: the jira ticket is to create both a tutorial and examples for this
module. This commit only contains the tutorial part. At this point, all
the submodules except the popover menu work by using the base submodule --
the popover one has to use the specific popover submodule.
Add basic color-picker example
AUI-1396 Create tutorial/examples for Alert
AUI-1396: Source Formatting
Add Alert examples