Make the "experimental" generator the default option.

[budzanowski]

It has been a long time since we have any indication that the feed generation is too slow. This is because we have introduced a new feed generator. It is still marked as experimental.

We should remove the experimental label and make the new feed generator the default option for all new installs.

TODO:

• Update the code so the new feed is the default option for new installs.
• Remove the experimental label
• Update the woo documentation.