add note that vignettes are fictional

lessons/intro.md

@@ -38,7 +38,11 @@ As you engage more with open-source software, you realize that most projects are
 :align: center
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 In an October 2015 [interview](https://web.archive.org/web/20180514095134/http://rtalbert.org/blog/2015/interview-lorena-barba), mathematics professor and blogger Robert Talbert asked this question: "Why do you advocate so strongly for open-source technology in research and education?"
-
+````{margin}
+```{note}
+The vignettes in this course are all fictional, except this one!
+```
+````
 > Free and open-source software (FOSS) is a human invention of tremendous impact. It poses an alternative to intellectual-property instruments that are limiting and want to control how a creative work is used. Open-source licenses allow people to coordinate their work freely, within the confines of copyright law, while making access and wide distribution a priority. I’ve always thought that this is fundamentally aligned with the method of science, where we value academic freedom and wide dissemination of scientific findings. ---**Lorena A. Barba**
 
 `````