hide code blocks in examples

[neuromusic]

Many of the examples have boilerplate code that downloads example data and performs required pre-processing before the useful part of the documentation starts. We'd like to hide this content as much as possible.

Possible solutions...

(1) hide it on the front end
We can leave the code as-is in the example sphinx gallery scripts and modify the output.

Options:

• make sure that tagged blocks don't render in HTML
• allow the user to toggle tagged blocks

(2) hide it in the API
We can minimize the boilerplate by adding components to the data module that give the user pre-processed data. This could be pre-processed data that we have stored on AWS, but there's a risk that this becomes out-of-date if there are updates to starfish in the future. Another option would be API components that wrap the current boilerplate and cache the results locally. The pre-processing steps would only happen the first time the code is called.