more FAQ

[prjemian]

• How should I do caget from a bluesky session? (use ophyd)
• How to remember things from one session to another? (use %run -i and write them down in files in ~/bluesky/user/)
• How to save/restore crystal orientation? (see https://blueskyproject.io/hklpy/examples/notebooks/tst_UB_in_descriptor_document.html?highlight=orientation#Restore-orientation-information, which should be in the howto section, not test)