Fix tiny typo in conf.py

[adamltyson]

I's look a lot like L's

[niksirbi]

I think this may not be a typo. URI = Unique Resource Identifier. URLs are a specific type of URI.

[niksirbi]

But there still may be an argument for 'fixing' it, since most people don't know what a URI is, and for all intents and purposes we mean URL. So I'll approve and let you decide.

[adamltyson]

Huh TIL! I think you should decide, as you know more than me!

I raised a few of these PRs, so we should be consistent either way!

[adamltyson]

Closing (see neuroinformatics-unit/movement#798 (comment))

[niksirbi]

In that case I'd say leave it as is. I think this comment comes from sphinx's own templates somewhere, and the original author (whoever that is) made an intentional choice to use URI instead of URL. Also linkcheck's own docs refer to "URI", see https://www.sphinx-doc.org/en/master/search.html?q=URI

So, I'd close the PRs.