feat: add optional wifi ap pw

[docgalaxyblock]

I added a wifi ap pw option to the substitutions.
The default is your current state of no pw.

I added a warning comment that if the user forget the pw it is required to open up the device again.
Therefore I added the hint to use the Setup code you can find at the Minis backside as the ap pw.

[klaasnicolaas]

I doubt whether it is useful to put these kinds of optional things in the YAML config, this could cause problems if a user in the future flashes their onju voice via ESP web tools.

[docgalaxyblock]

@klaasnicolaas What scenario do you have in mind? Cause after my change the default is still no ap pw at all.

[klaasnicolaas]

My advice would be not to merge optional code, if users would like to use a AP password they can add and compile it themselves.

./Klaas

[docgalaxyblock]

@tetele What is your opinion?

My intention is to give users a hint regarding securing up their onju fallback ap.

[tetele]

AP password is very rarely needed and, if so, the user should probably go for a custom config. I agree with Klaas.