Develop a Chrome Extension for Gmail

HELLO!, this project is essentially for me as I am always frustrated that I can't do this when I am drafting gmails... I would like to develop a a chrome extension that works specifically with gmail. I would like the extension to add a plugin or button into the gmail app so that when I am writing an email, I can click a button and then draw directly into the email with my mouse. E.g. I would be typing this email to you in gmail and I want to highlight the HELLO! so I click the extension button and then I can draw a circle around the word HELLO to highlight it; this will then get sent with the email. I have included an attachment of the gmail email composing window and you can see bottom left there is a small button from GIPHY which instantly allows you to add GIFS to email. Ideally it would work like this and be this easy Are you able to build this for me? Regards Phil