Update RSE attributes documentation. Resolves #399.

[bjwhite-fnal]

Here's a first draft of trying to document all of the remaining RSE attributes, and tweaks to the existing documentation.
@bari12 @voetberg I'd value your input on a review of this.

[voetberg]

All really good additions! I think we can add more though. Would it make sense to group attributes by things specific to tape RSEs, and things controlling transfers? Makes it easier to scan through and find exactly what you're looking for.

I think it would also be very useful to have an example or two for maybe ""typical"" use cases (settings you'd want to set for tape rses, things you're change when you're setting up a non-posix rse?) It's annoying for me not to have an operator's knowledge here, but are there a few clusters of RSE-types that exist? Surely there's a decent bit of commonality

[bjwhite-fnal]

@voetberg I think that's a good idea to give a more comprehensive example. However, I think this page should just list every available option.

Maybe we should instead modify this section of the "configuration" page, which is already sort of trying to do that. The given RSE there already wouldn't work for transfers, since it doesn't have an fts (or some other transfer manager) configured.

[voetberg]

@voetberg I think that's a good idea to give a more comprehensive example. However, I think this page should just list every available option.

Maybe we should instead modify this section of the "configuration" page, which is already sort of trying to do that. The given RSE there already wouldn't work for transfers, since it doesn't have an fts (or some other transfer manager) configured.

That would be fantastic! The code on that page is quite a bit too generic to really be helpful

[rdimaio]

Suggested change

	- **extract_scope**: _(Optional)_ Default: `atlas`.
	- **extract_scope**: _(Optional)_ Default: `def`.

This has been changed recently, see: https://github.com/rucio/rucio/blob/3d5cbf5d8c0e37f793bbd6f01d1064e44cfe0b4f/lib/rucio/common/utils.py#L577