Superset: Improvements following user testing

[e-belfer]

Following the first round of user testing, we should make some key improvements to Superset in preparation for a second round of asynchronous user tests. This includes issues descoped in #3867 and any key improvements identified in user tests that must be fixed prior to a public beta launch.

Critical Infrastructure Problems

Beta Give feedback

1. Figure out permissions problems with auto-complete and samples
2. Debug auth0 problems with Github

Documentation Gaps

Beta Give feedback

1. Document annotation layers
2. Document filtering using LIKE and ILIKE - why doesn't this work as expected?
3. Document: changing the name of the series on the legend
4. Add a note on citing PUDL

Infrastructure Gaps

Beta Give feedback

1. Get rid of the bar for numeric fields in table charts
2. Figure out if we can spruce up the auth0 text
3. Customize the home page - e.g., https://medium.com/towards-data-engineering/customize-apache-superset-home-page-to-fit-any-html-block-85f8d4b58419. Alternatively, figure out how redirect or emphasize the welcome dashboard.

Problems to investigate

Beta Give feedback

1. Chart titles - see Configuring chart title, image size and resolution, and file name on export apache/superset#30619
2. Chart export options - pick DPI and custom width and length? - see Configuring chart title, image size and resolution, and file name on export apache/superset#30619
3. Change chart names on export - see Configuring chart title, image size and resolution, and file name on export apache/superset#30619
4. User permissions (as discussed in Make superset dashboard improvements for user testing #3867)
5. Change CSV/Excel names on export - see fix(excel/csv filename on chart download): downloads zip file and excel/csv file with chart name. apache/superset#27409
6. Can save permissions be turned off by default? Would the button still show up? - can publish on Superset might be an option to toggle here