Pingora tutorial start added

[HasturDev]

I created the folder and a start.md so that you could look it over and decide if this is the type of tutorial you would want for pingora

[HasturDev]

The intent of this push is to make sure that you guys are happy with how the tutorial is written.
I will generally write the rest of the tutorials in the same way so if there's any changes you want made or updates then it will be helpful when I write the rest of them.
I've also added all of the stand alone files for you guys so you can determine if there's more code in each file that you would want to add because you want me to talk about that specific thing

[HasturDev]

@johnhurt what changed that made this pass checks?

[johnhurt]

It looks like it was one of log's dependencies that introduced a feature incompatible with our msrv. We had to fix it internally, and you reap the benefits 😛