I start to make a child-template for persona.
The modifications will be light as some style change, add widget zones for categories, etc.

I also would like to use a svg as logo and i would like to respect the flexibility and the back office structure.

As i begin, i would like to know, is it possible to add field into settings page from the template?
For my example, i would like to add an additionnal upload field into the general settings page?
One for the svg, the other one for the png fallback.

Another idea, add a check box for a no index option?
Maybe i have to creat a plugin, maybe it is an option in headers on the advance settings page (i don't understand what is it about?).

Thank you in advance for any help.