add hugo-conference theme

[jweslley]

Until now, Hugo hasn't any theme to help create conference/event sites.

[CLAassistant]

All committers have signed the CLA.

[digitalcraftsman]

Hello @jweslley

thank you for sharing the theme with the Hugo community 👍 A conference theme is definitely new and fills a gap in Hugo's theme portfolio.

Let's take the last mile please to get your theme merged. While building the theme site locally with your theme I noticed a few smaller issues:

• please make sure that the thumbnail and screenshots have right dimensions. You can find them in the README.
• please a neutral base url such as https://www.example.com (read here why)
• please a neutral link for the call to action button and logo in the sponsors section as we try to avoid promotions for commercial services in the demos. Most people outside of Brasil are also unlikely to follow the instructions of Eventick's website

[jweslley]

@digitalcraftsman I fixed the issues. It's done! 😄

[digitalcraftsman]

Thanks. I've merged your pull request as a883250. Your theme should appear soon on the theme site. Furthermore, I'll promote your theme on Hugo's official Twitter account.