Add "permission denied" FAQ entry

[wilyJ80]

Given the 50+ results for this "permission denied" error when uploading a sketch to the board in the forum, this entry was added to the FAQ. This might be desirable to have in an easily accessible page given it's a necessary step to take to get started with the microcontroller.

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[matthijskooijman]

Looks good to document this. I would suggest:

• Making it a bit clearer that this works on Linux
• Clarify that this command works on most Linux distributions, but the exact command (group name) might be different on differnet distros (maybe also add an ls -l /dev/ttyACM0 command or so to help people figure out the command they need.
• Maybe adding a command id | grep dialout or cat /dev/ttyACM0 they can use to verify if this is actually the problem and this fix is appropriate.

I realize that adding all these things might result in hairy and hard-to-read FAQ entry, so maybe not everything should be added (or maybe you can find a wording and structure that balances readability and completeness...).

[wilyJ80]

Pushed some changes. Tried to keep things concise but still reliable as suggested. Thanks for the suggestions, I'm learning more and more about the software side of Arduino.

[alessio-perugini]

@wilyJ80 Thank you for opening this. I see that it was committed the compiled binary in b41effc do you mind removing it?

[wilyJ80]

Removed the binary directory. Is it OK now? Thank you for the patience. I'm starting out with contributing with this community. 😄

[alessio-perugini]

@wilyJ80 Yup, thank you for bearing with us! 😄

[matthijskooijman]

Hm, I'm a bit late to the party, but the documentation now just says "your group name", without any reference to how to figure out this group name, which is probably not very actionable for most users. I would suggest to use dialout in the example commandline and then say something like "The group name must be the owning group of the serial port (e.g. /dev/ttyACM0), on most Linux distributions it is dialout"

[alessio-perugini]

@matthijskooijman Oops, I missed that it was later changed into <group> somehow I managed to still read it with dialout.
@wilyJ80 if you don't mind I'd open a quick PR adding the suggestion of @matthijskooijman .
Sorry about that 🙏 , I guess I have to change my 👓