Use re-rendering for specification page with Markdown

[Tobias-TH]

The quality criteria on the specification page originate from Markdown content in the descriptions of node and property shapes. All descriptions contain tables that need to be formatted. For this, a CSS file is used because Svelte ignored selectors like table in <style> tags. This is because these tags are added at runtime.
Use re-rendering so that the style can be defined in the file SpecificationPage.svelte.