Automate fetching of PTAU ceremony

[pajicf]

What does this PR resolve? 🚀

• Adds ptau.sh bash script for ptau fetching

Details 📝

Makes it faster and easier to fetch the ptau file and parameterises the power so it's consistent across other scripts.

Checklist ✅

• I have merged the main branch into my branch and resolved all conflicts
• I have documented the new code
• I have smoke tested the new code locally

[dryajov]

Looks useful, @bkomuves

[bkomuves]

Looks useful, @bkomuves

I kind of intentionally didn't automate this, as I feel downloading 2-5 GB files should be not triggered without the user knowing what they are doing, and it only has to be done once anyway.

And it's not really more complicated to follow the instructions than to run the script.

And of course this is not something a typical user should do at all, this is more an explainer intended for internal use.

[pajicf]

They'd still have to run the script themselves, it's more of just simplifying the manual step rather then it being automated

[bkomuves]

My reasoning is that this step is something:

• you should be aware of why is it there (it could be explained better), and what it does exactly
• and you run it only once anyway

So I would prefer to keep it this way. The explanation could be certainly improved. And since it's not a user-facing thing, I think 5 lines of bash command, out of which 1 contains the essence and the rest is boilerplate like moving around, is fine, instead of having a script.

While the rest of the scripts are to run every time either the circuit or some parameters change. I ran those several times just today. But I haven't downloaded the ptau ceremony again. So this is different from the rest of the scripts.

Sorry, I usually have strong opinion on things ¯\_(ツ)_/¯

[bkomuves]

A compromise could be to add the script, and add it as an option in the README, but not deleting the original instructions.