self: shrubs render themselves

[hanfel-dovned]

blue is good for overlays

mast is good for recursive rendering

??? is good for non-overlay, non-recursive rendering

Add a third rendering methodology, self, which simply passes http requests to the shrub specified in the path. If Sky doesn't know about any other strategies for this path (which will typically be the case), it should use self as the default rendering framework.

[hanfel-dovned]

The Sky navbar now displays three hardcoded renderer options: hawk, tree, and self.

Next Up:

• For apps we want to keep around, rewrite all hawk renderers to self and obfuscate this option from the UI, routing to self as the default
• If a dev wants to use mast as their default renderer (or blue, for whatever reason), they should poke that strategy into Sky in that imp's init arm
• If default rendering nacks, redirect to tree
• For overlays and other renderers, users should still be able to type in a strategy, and if this succeeds, there should be a UI element for saving it (as well as un-saving)