Fix filename for slide/poster metadata

Author: fwkoch

README.md

@@ -520,7 +520,7 @@ Editors should come to a final 'ready', 'unready' decision before the **Final Ed
    4. SciPy tools plenary slide decks (tools)
    5. 45-minute keynote slide decks (keynote)
 5. Choose the appropriate folder, and make a new directory inside it (it needs a unique name)
-6. Copy your slide deck or poster into the directory, and add a file called `info.json` with the following fields needed for uploading to Zenodo (using an empty string for author orcid or
+6. Copy your slide deck or poster into the directory, and add a file called `myst.yml` with the following fields needed for uploading to Zenodo (using an empty string for author orcid or
    affiliation if these cannot be provided):
 
 ```yaml