Update user guide

[mgalloy]

We need to update the user guide in light of changes for 1.0.11.

Changes

• different averaging with different filenames, i.e., "daily" synoptic files, for Use simple averaging selection criteria #208
• update header tables to reflect the new metadata.
• update user guide to reflect moving the tuning/continuum information from L1 primary to extension and deletion from L2.

[jburkepile]

The current guide does NOT specify that UCoMP brightness is in units of DISK CENTER INTENSITY

• Add ' disk center brightness' in the user guide in the various places that only specify the units are in disk brightness.

[bberkeyU]

Document the tuning/continuum information in the header, including updates that move tuning (cont???) information from the L1 primary header to the extension. And remove the tuning from L2.