docs: improve "Quick Start" documentation in top-level and sir example READMEs

[LSarribouette]

Fixes #564

Improves the documentation related to discussion #559.

Edited by Chris to retroactively reference a new issue describing the changes.

[LSarribouette]

Hi! It is my first fork and pull request on someone else's repo. Please let me know if I should do anything differently :)

[chrispcampbell]

Hi @LSarribouette, thanks for taking the time to contribute these edits!

Your discussion thread prompted me to finally address #335 today (which I will merge and release tomorrow). That will render your proposed text somewhat inaccurate, so I will need to change it a bit before merge, and I will work on that tomorrow. I will probably move part of the text to a "troubleshooting" section in the wiki.

In any case, I appreciate your edits because they make it more obvious where I can improve the docs.

It is my first fork and pull request on someone else's repo. Please let me know if I should do anything differently :)

You did it correctly, and you even included a well-formatted pull request title, so all good from my perspective :)

[LSarribouette]

Awesome, thanks for your work!

[chrispcampbell]

I updated your PR per my previous comments, so the text is different than the proposed but the areas touched are the same, and we now point to the wiki page with a new "Troubleshooting" section (that page will be good to flesh out as time goes on). Thanks again for pointing me in the right direction!