Merge basic and full markdown renderer (#1040)

The original idea of the basic-markdown-renderer and the full-markdown-renderer was to reduce the complexity. The basic markdown renderer should just render markdown code and the full markdown renderer should implement all the special hedgedoc stuff like the embeddings.
While developing other aspects of the software I noticed, that it makes more sense to split the markdown-renderer by the view and not by the features. E.g.: The slide markdown renderer must translate <hr> into <sections> for the slides and the document markdown renderer must provide precise scroll positions. But both need e.g. the ability to show a youtube video.

Signed-off-by: Tilman Vatteroth <tilman.vatteroth@tu-dortmund.de>

src/components/markdown-renderer/replace-components/task-list/task-list-replacer.tsx

@@ -8,10 +8,12 @@ import { DomElement } from 'domhandler'
 import React, { ReactElement } from 'react'
 import { ComponentReplacer } from '../ComponentReplacer'
 
+export type TaskCheckedChangeHandler = (lineInMarkdown: number, checked: boolean) => void
+
 export class TaskListReplacer extends ComponentReplacer {
   onTaskCheckedChange?: (lineInMarkdown: number, checked: boolean) => void
 
-  constructor(onTaskCheckedChange?: (lineInMarkdown: number, checked: boolean) => void) {
+  constructor(onTaskCheckedChange?: TaskCheckedChangeHandler) {
     super()
     this.onTaskCheckedChange = onTaskCheckedChange
   }