Small edits to tutorial documentation.

[mgjarrett]

I noticed a couple of small things that could/should be changed when scanning through the tutorial documentation recently. I think these are too small to warrant a formal issue, but it is still worth making the changes.

[john-science]

First off, don't worry about an issue for something like this. Our PRs represent a good traceable record, as do our commits.

And thanks so much for the cleanup!

I haven't tried to build your change yet, but one thing pops out at me. I'm not certain, but could we change this:

[Building input files for a fast reactor](https://terrapower.github.io/armi/tutorials/walkthrough_inputs.html)

to this?

[Building input files for a fast reactor](walkthrough_inputs.html)

I am just thinking the relative path would be safer in case someone builds and deploys the documentation locally for testing.

[mgjarrett]

Looks good to me. I initially attempted to link to the page using a reference in Sphinx but it wasn't working, so I just went with a URL. I didn't know this type of relative path would work, but I'm all for it.

[john-science]

Looks good to me. I initially attempted to link to the page using a reference in Sphinx but it wasn't working, so I just went with a URL. I didn't know this type of relative path would work, but I'm all for it.

Sorry, just to be clear: I haven't actually tried it, I just assume it works. Have you tried making the docs yourself?

tox -e doc

[mgjarrett]

I did try myself to confirm it would work before pushing. I didn't try tox -e doc, but it did work with make html. I'll try tox now, but it should work.

[john-science]

Looks great!

Sorry for the hassle, it'll be smoother next time.

I just love having help with all these docs!

[john-science]

Merged!

Thanks @mgjarrett !