Following the review of #3177 and an enlightening conversation with Bouwe on how to review recipes and diagnostics, there are several issues to fix with the radiation budget recipe:

• Add a copyright statement, see Implied heat transport new diagnostic #3177 (comment)
• Update the documentation so that it renders correctly, see https://docs.esmvaltool.org/en/latest/recipes/recipe_radiation_budget.html
• Ensure the provenance is correct and used appropriately, see Implied heat transport new diagnostic #3177 (comment)
• Add Jon and myself as authors of ESMValTool on Zenodo, see list of authors
• Add a reference, see https://docs.esmvaltool.org/en/latest/community/diagnostic.html#adding-references