0004/event add singular event page html

[BlkPingu]

single events are shown with all their properties in this html

elements:

• [x] title
• [x] date
• [x] time (from- to)
• [x] location (with map?)
• [x] URL
• [x] description
• [x] ersteller/in

nice-to-have:

• [ ] eventbanner (png?)
• [ ] access (/view rights)
• [ ] share event (json?)

[BlkPingu]

re-assigning to milestone alpha, and adding label enhancement since all the requirements are met and only being improved upon