The `Standorte` slug is currently fixed for all websites

These are basically three problems to fix.

• Currently the url for each location has to include Standorte. This can be fixed by making the string /standorte/ in the fetchChapters function in fetch.ts dynamic.
• Additionally the src/routes/standorte/[slug] folder is used to render the location websites. The standorte has somehow to disappear from the slug
• The main locations website is described in src/routes/standorte/+page.svelte. Also here the standorte needs to be exchanged somehow...