Update footer.md (#756)

docs/sections/footer.md

@@ -7,7 +7,7 @@ However, there are two configuration points where you can add items to your foot
 
 `html_theme_options["footer_start"]` accepts a list of HTML templates that will be placed at the beginning (left on most screens) of the footer.
 
-`html_theme_options["footer_start"]` accepts a list of HTML templates that will be placed at the end (right on most screens) of the footer.
+`html_theme_options["footer_end"]` accepts a list of HTML templates that will be placed at the end (right on most screens) of the footer.
 
 For example, the configuration below assumes there is a template at `_templates/test.html`.
 It adds the `_templates` folder to Sphinx's templates path, and adds the template to both the start and end section of the footer.