Update dev docs

[sonnyp]

Fixes #603

[sonnyp]

@ethanjli could you follow the steps in this PR and let me know if it works for you?

[ethanjli]

Test report

After I added the described snippet to ~/.ssh/config on my computer and ran ssh pi@$planktoscope (where $planktoscope is home.pkscope for me), I got this message before the password prompt: no such identity: /home/lietk12/.ssh/planktoscope: No such file or directory. The updated enable-developer-mode script completed without any errors. After I registered the new SSH key with GitHub and then ran git remote set-url origin git@github.com:PlanktoScope/PlanktoScope.git and git pull, the pull failed with the Permission denied (publickey) error.

Then I edited ~/.ssh/config so that the last line would correspond to IdentityFile ~/.ssh/$planktoscope instead of IdentityFile ~/.ssh/planktoscope. This time, ssh pi@$planktoscope worked without a password prompt. However, git pull still failed with the same error; running ls ~/.ssh showed that it just had two files, authorized_keys and known_hosts. Does this mean that I never set up SSH agent stuff on my computer, or is the guide missing an expected manual step for copying the $planktoscope ssh public key from my computer to the PlanktoScope?

Requested changes

GitHub won't let me do a "suggest change" because this PR never touched the relevant line, but the IdentityFile line of the # Add the following to ~/.ssh/config code block needs to be changed from:

  IdentityFile ~/.ssh/planktoscope

to:

  IdentityFile ~/.ssh/$planktoscope

[sonnyp]

Does this mean that I never set up SSH agent stuff on my computer

You shouldn't have to do anything besides what's described here.

or is the guide missing an expected manual step for copying the $planktoscope ssh public key from my computer to the PlanktoScope?

That's what ssh-copy-id -i ~/.ssh/$planktoscope.pub pi@$planktoscope does

But it's unrelated to agent forwarding. ForwardAgent yes in .ssh/config should be enough.

Can we have a quick look together after the software meetng ?

[sonnyp]

I fixed

Requested changes

thanks.