docs: update rendering instructions (#62)

Co-authored-by: Christoph Sax <christoph.sax@gmail.com>

Author: maelle

README.md

@@ -3,8 +3,7 @@
 ### Render
 
 - install [Quarto](https://quarto.org/docs/get-started/);
-- run `quarto render`;
-- the output is in `docs/`. To serve the folder, in R you can use `servr::httw("docs")`.
+- run `quarto preview`.
 
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