Markdown render error causes "file not found"

[jannis-baum]

Problem is here:

Vivify/src/routes/viewer.ts

Lines 53 to 56 in 140ad19

	body = renderTextFile(data.toString(), path);
	}
	} catch {
	res.status(404).send('File not found.');

To reproduce, create a file with a duplicated custom id, e.g. by copying the whole "tests/markdown-extended.md" file and pasting it below itself again

Solution: handle render errors separately and give proper description