Adding example awareness to bayesian teleprompter

[klopsahlong]

This PR makes the following changes:

1. Adds support for example aware metaprompting. Now users have the choice of using both data aware and example aware metaprompting, either together or separately. These choices can be specified with the view_data and view_examples flags.
2. Adds in a summarization step on top of data observations in order to condense observations into a 2-3 sentence summary. We've found that this helps to make suggested instructions better, potentially because the metaprompt is less bogged down by extra text. (thanks @XenonMolecule for this solution!)