Add glossary of terms to click reference docs

[Rowlando13]

Add a section to the general reference docs for glossary of terms.
Should contain ambiguous terms that defines how we use them in our docs. It allows us to be internally consistent in our usage

• Option
• flag
• command line application
• command line utility
• terminal

[Nemoooo22]

Hey. Mind if I take this?

[Rowlando13]

Sure!

[HanslettTheDev]

Hello there, when you say add a glossary of terms under the General reference, I'd like to ask what are some of those Ambigious terms that should be present there, this would give me a better understanding of the words that need to be added into the glossary?