resultlist_recursive_markdown: Rmarkdown from resultlist in specified hierarchical order
In mabafaba/hypegrammaR: A grammar of hypothesis test driven analysis

Rmarkdown from resultlist in specified hierarchical order

resultlist_recursive_markdown(resultlist,
  by_analysisplan_columns = c("dependent.var"), by_prefix = c("",
  "subset:", "variable:"), level = 2, render_result_with,
  questionnaire = NULL, label_varnames = TRUE)

`resultlist`	structure like the output from from_analysisplan_map_to_output: A list with two items "analysisplan" and "results": The "analysisplan" as a data frame, where each row must match a result in a list of "results"
`by_analysisplan_columns`	vector of strings matching column names of the analysisplan. The first element becomes the main heading, the second element the sub-heading etc.
`by_prefix`	a prefix added at the beginnig of the headline; same length as 'by_analysisplan_columns'
`level`	the markdown header level to start with; defaults to 2 which leads to "## heading", i.e. the second header level.
`render_result_with`	a function that takes a single result as input and returns an rmarkdown formated string
`questionnaire`	optional; the questionnaire (koboquest::load_questionnaire())
`label_varnames`	wether variables names should be labeled in headings