docs: Tighten up general requirements list
Simplify the bullet list of general requirements in the documentation
requirements document at the same time as making the wording
unambiguous.
@@ -13,8 +13,10 @@ Containers](https://github.com/kata-containers) project.
# General requirements
-- All documents are expected to be written in [GitHub Flavored Markdown](https://github.github.com/gfm) format.
-- All documents should have the `.md` file extension.
+All documents must:
+
+- Be written in [GitHub Flavored Markdown](https://github.github.com/gfm) format.
+- Have a `.md` file extension.
# Notes
