Section order, pipeline output, packit tests

• Convert smoke test into docs test, fix config file
• Include a short summary in the help usage message
• Enable simple smoke test in the testing farm
• Add nitrate back into the package requires
• Enable custom tarball in Packit to fix man page
• Mention custom plugins config on the plugins page
• Enable copr builds and add packit config
• Custom eprint() is no more necessary [fix #211]
• Convert custom section order to int [fix #212]