readme: replace banner logo with the one using paths for text

README.md

-<img src="https://git.pleroma.social/pleroma/pleroma/uploads/021b5f7735fd15f6c5f0f25501958f2a/pleroma-banner-vector-nopad.svg" width="300px" />
+<img src="https://git.pleroma.social/pleroma/pleroma/uploads/8cec84f5a084d887339f57deeb8a293e/pleroma-banner-vector-nopad-notext.svg" width="300px" />
 
 ## About