Change default behavior to lazy loading

[choldgraf]

Description / Summary

We currently allow for lazy loading of pages (so thebe JS only loads if certain node types are on a page etc) behind a feature flag. This is because we didn't want it to be too disruptive as the kinks were ironed out.

Once #34 is satisfied we should make the default behavior "lazy load".

Value / benefit

This will save a lot of JS time loading for people.

Implementation details

No response

Tasks to complete

• Allow loading logic that doesn't depend on ThebeButtonNode #34
• Change the default here

[choldgraf]

closed by #41

[choldgraf]

@akhmerov would you be willing to try this out in the contexts you're using this extension (if you are) on the master branch, to make sure we didn't break something by switching to lazy loading?