[WIP] Migrating to new theme and building the website again

[jyoti-bhogal]

This PR is being used to migrate to a new theme and to build the entire website again.

• [x] https://github.com/researchsoft/website/issues/27
• [x] https://github.com/researchsoft/website/issues/30
• [ ] https://github.com/researchsoft/website/issues/32