refactor: define RP and OP abbreviations with parentheses

[MatteoGauthier]

Summary

I was reading the docs when I didn't understand some of the abbreviations. So I added brackets to the first occurrence of the terms RP and OP that I didn't understand. According to this guide for writing https://www.mcc.gov/resources/story/section-writing-guide-good-grammar/

Idea: a glossary of terms used in the docs

[charIeszhao]

Thanks!

But please do update your Git commit message and PR title to this format in order to pass the CI checks:
refactor: define ...

Edit: Nvm, I've updated them for you.

[MatteoGauthier]

@charIeszhao thx !