Revised login guides, new "basic shell commands" guide, custom CSS

[xamberl]

Major changes

• Added Basic Shell Commands
• Added custom CSS, particularly adding a new block quote style that can be enabled by appending {:.tip-header} and {:.tip} to block quotes. See an example here.

Less major (but still not minor) changes

• Revised Log in to CHTC, including a new table with SSH programs
• Revised Automate CHTC login

[xamberl]

@CannonLock Can you specifically review the CSS? I hacked this together, but I want to ensure that this is okay to do, or if there's another way to implement this kind of formatting.

[ChristinaLK]

I think this looks great! Things I'll want to discuss at some point:

• items that fall under "style guide" - agreeing on how we capitalize headers, and confirming that we want to remove outline numbers/letters in our headers(I'm in favor esp now that we have clickable headers, just want to document).
• sort of related -- going through a few guides together and how we would restructure them to match the format you've created here.
• I see the summary possibly getting out of date because we forget to update it as we update the page. 😅
• What are your thoughts on adding some more formatting to our header styles to better distinguish levels 1 - 4? We did this on the OSG docs (a little) and it looks like this: https://portal.osg-htc.org/documentation/htc_workloads/using_software/containers-singularity/

I LOVE the way it looks to have the 2FA video in its own "tip" box. If we make a bunch more videos, that's a good model for integrating them. Ditto having the table of ssh tools - am realizing we could use those a LOT MORE in our docs and that's a great use case.

I added the suggestions about Option 1 vs Option 2 -- not sure if that's strictly necessary, but I like to clarify when two headers are sequential / additive vs disjoint, if that makes sense? But I also don't need to die on that hill, partially because I don't like the way it looks - I prefer the simplicity of just the header name. :)

[aowen-uwmad]

Good to go after addressing comments.

[CannonLock]

LGTM.