Random delay option

[notklaatu]

Creating multiple posts instantly may get a user banned from their instance.
I've added --delay option to randomly pause between posts.

I removed the continue statement in the --dry-run block and added an if not statement. The new logic is:

• If it's a dry-run, print a message to stdout
• If it's NOT a dry-run, create the post
• If --delay is true, then delay a random number of seconds (between 10 and 30)