Adds logo and favicon.

[jack-morrison]

Fixes #6

[grahamlopez]

So this looks nice. However, from a UI perspective, the logo says "OLCF ..." but actually links to documentation homepage. Confusing?

[jack-morrison]

Hm. That's a good point. Maybe we could add a "back to olcf.ornl.gov" button? I think the action of clicking on the RTD logo area should keep a user inside of the docs, but am open to being convinced otherwise.

[grahamlopez]

yeah, it is obviously standard for the RTD theme for the icon to take you to the home page, so probably want to keep that. I wonder if we can change the logo image so that is more clear, and we'll have backlinks to OLCF elsewhere in the page(s)

[jack-morrison]

I'd be in favor of putting backlinks to olcf.ornl.gov in place of View Page Source in the top right of all pages.

I asked @tom-papatheodore about this and he also suggested a change to the logo graphic.

[grahamlopez]

sounds fine to me

[jack-morrison]

@grahamlopez so, it's pretty hacky, but what do you think of the Back to OLCF.ORNL.GOV in the left hand nav? I know it adds some matching body text, but that can be hidden with some CSS.

If this type of custom javascript + CSS injection isn't the business we want to be in, we can drop this altogether. I'm trying to:
[1] Maintain that clicking the RTD logo area keeps you inside the docs.
[2] Maintain the upper right 'Show page source' text, since a future issue could address adding GitHub integrations there (like Spack's RTD)
[3] Provide a user-friendly and obvious way to get back to the OLCF homepage.

While this approach uses :caption:, it shouldn't bar us from using :caption: elsewhere since the styles are only applied to specific caption elements.

[jack-morrison]

Closing, as this work (and other header/footer integration) is being picked up by Brian Gajus.