Add documentation for use of SAM

[MikeLippincott]

          Some other comments I have:

1. In this notebook, you create a directory for the 3.sqlite_output. I do not see this directory in the PR, and I am curious why it is created here and not in the feature extraction folder where you use CellProfiler to output an SQLite file.
2. In code cell 4, there is commented-out code. I recommend removing this commented-out code if it is not used.
3. This might be beyond the scope of this PR, but in a README, I would recommend describing SAM and how it works. Are there any parameters you need to set? What are the functions that you use? What is the output?

Originally posted by @jenna-tomkinson in #1 (comment)