tom_setup: remove Sidereal/NonSidereal "default" question from script

[phycodurus]

This just raises needless questions for new users.
This is also probably true for the question about hints as well.

[jchate6]

For the record about what these setting do:
From what I can tell, the only thing Sidereal/NonSidereal "default" setting does is determine which target tab is displayed first when creating a completely new empty target.

Hints toggles whether "hints" are used throughout the TOM by adding a "hint" to the messages on page load. currently this is used to add a single hint:

'Did you know updating observation statuses can be automated? Learn how in'
 '<a href=https://tom-toolkit.readthedocs.io/en/stable/customization/automation.html>'
 ' the docs.</a>'))

to the Target detail page, the observation list page, and the data product update page.

I actually didn't know how hints work. I quite like this functionality and think we should expand on its use.

I'd recommend:

• removing the Sidereal/Non-Sidereal choice
• setting Sidereal as default
• removing the Hint Choice
• set hints = true in settings by default
• Make "hints" a user profile field that is the same as setting.hints by default
• adding a "Remove Hints" link to every hint via tom_common.hints.py that will set hints to False in the current User's profile
• Add a hint to the Target Creation page letting people know they can change the default
• Add a bunch more hints about potential customizations and links to the documentation.

Alternatively, we can remove the hints from the settings all together and just have them on by default for admin and off for regular users.