Flip the client secret and client ID in the README.md

[quicksketch]

I copy/pasted the lines from the README.md into my settings.php file:

Optionally you can store client_id and client_secret via settings.php

$settings['githubapi_client_secret'] = 'YOUR_APP_CLIENT_SECRET';
$settings['githubapi_client_id'] = 'YOUR_APP_CLIENT_ID';

But these settings are flipped from the UI in GitHub:

To avoid confusion, we should flip the settings in the README to prevent this same copy/paste mistake.

[quicksketch]

Fixed this in https://github.com/backdrop-contrib/githubapi/commit/6bcde6a4d92331f6682448e8b67f58a93a4fbf9c.