[Feature] Document the use of keys.txt in the readme, provide dummy keys.txt file with dummy data

[observeroftime02]

Is your feature request related to a problem? Please describe.
When launching NUT without a keys.txt file, the application complains on the command line that "could not load keys.txt, all crypto operations will fail". Trying to find out what sort of format the application expects is challenging, because it is not documented in the readme. Not everyone can read and understand the source to figure out the proper layout of the file.

Describe the solution you'd like
Provide an example in the readme, such as "place a file called keys.txt in X directory, the entries should look like Y". I can guess it wants my prod.keys file, however that file is a binary, not a text file. Having an example entry with dummy data would help me format the text file correctly.

It would also help if I could find out what operations keys are required for, to determine if I should bother creating such a file in the first place. The current description of "crypto operations" is pretty vague for the average user. I'm assuming it is related to the compress / decompress options?

Describe alternatives you've considered
Searched the issue tracker for a solution or answer, found none.

[Fronti]

You mean like keys_template.txt?

Btw, prod.keys is a text file. Just rename it to keys.txt and it'll be happy.

[observeroftime02]

🤦‍♂️I swear I have a special kind of pigeon brain sometimes. Thank you! In my defense, the file did not exist as part of the download.

It might be worthwhile pointing the existence of this file out in the readme (for people such as myself), other than that, suggestion can be closed. Everything is working.