Update CONTRIBUTING.md

Oxford comma && nomenclature

Author: pythoninthegrass

CONTRIBUTING.md

@@ -13,11 +13,13 @@ Please note we have a code of conduct, please follow it in all your interactions
    [extension](https://editorconfig.org/#download) to keep formatting and linting consistent across 
    the repo's code base.
 3. Create a new `<name_of_topic>.md` under the `markdown` directory in place of a traditional
-   `README.md`. Note the lowercase [snake_case](https://betterprogramming.pub/string-case-styles-camel-pascal-snake-and-kebab-case-981407998841) style formatting.
+   `README.md`. Note the lowercase 
+   [snake_case](https://betterprogramming.pub/string-case-styles-camel-pascal-snake-and-kebab-case-981407998841) 
+   style formatting.
 4. Update the `<name_of_topic>.md` with details of changes to the interface, this includes new 
-   environment variables, exposed ports, useful file locations and container parameters.
-5. Any relevant images should be stored in the top-level `img` directory and embedded within
-   the `<name_of_topic>.md` document.
+   environment variables, exposed ports, useful file locations, and container parameters.
+5. Any relevant images should be stored in the top-level `img` directory, `<snake_case_style>.png`, 
+   and embedded within the `<name_of_topic>.md` document.
 6. You may merge the Pull Request in once you have the sign-off of the repo maintainer.
    If you do not have permission to do that, you may request the reviewer to merge 
    it for you.