Cleanup root

[Dr-Electron]

Is your feature request related to a problem? Please describe.

With the upcoming changes we should cleanup the wikis root so that it is easier for us and others to make needed changes

Describe the solution you'd like

### Tasks
- [x] Move `plugins` into `src` folder
- [x] Get rid of `theme` and move components to `src` folder
- [ ] Get rid of `tutorials`, move content to docs and configure tutorial cards in a separate config file
- [ ] Rename `common` folder to `config` and move all relevant configs there