Add guidance around "email" and "email address"

[chloeredhat]

When technical writers use the term "email" it causes issues for machine translation. In English, "email" is often used to refer to "email address" as well as "email message," but in other languages, like Japanese, these are two different words.

We should add guidance since IBM does not have any.

This issue is also documented on the Loc team's spreadsheet: https://docs.google.com/spreadsheets/d/1eGL0d3FGTsaL0n6ysCa_JnuYW2cirr-UstQnyoC10gA/edit?usp=sharing

This issue came up because all HCC products were instructed to add this note to the docs:
NOTE: You cannot log in to the Hybrid Cloud Console with your email unless your email is your Red Hat login. For more information, see link:https://docs.redhat.com/en/documentation/red_hat_hybrid_cloud_console/1-latest/html-single/getting_started_with_the_red_hat_hybrid_cloud_console/index#finding-login_getting-started[Finding your login].

I've already given the Loc team a heads up so that this will not be translated incorrectly, but if I hadn't, we might've spent more time and money on translation.

[roldanbob]

Glad to see this call for clarification. Using email in place of email message or email address is one of my pet peeves!

[IngridT1]

@chloeredhat If you want to open a PR for this, I think this is worth adding for the translation benefits.