HTML Multiresolution image?

Hello, iam going to be honest with the truth.

i have a gmod server and i want to punt the rules in the MOTD but the image at low resolutions looks very big

Image for problem

I dont speak english, use translator sorry for bad.

I was researching on the internet and they told me that if I used html they could make the image look good in all resolutions

I am a noob of html, could someone send me a guide to start using that language?