Source locations are misleading with include shortcodes #310
Description
As quarto resolves the include shortcodes before it sends QuartoNotebookRunner the final markdown, an error in file B.qmd line 100 that's included in A.qmd at line 200 would show the error to be at line 300 in A.qmd which is confusing. Probably, we should detect include shortcodes, read in the included files and resolve line numbers manually.