fix(img): Remove global CSS rules for images in prosemirror

We have a custom node for displaying images anyway.

This fixes the cursor being a pointer in the preview images of preview
links.

Signed-off-by: Jonas <jonas@freesources.org>

Author: mejo-

src/css/prosemirror.scss

@@ -177,11 +177,6 @@ div.ProseMirror {
 		font-size: var(--default-font-size);
 	}
 
-	img {
-		cursor: default;
-		max-width: 100%;
-	}
-
 	hr {
 		padding: 2px 0;
 		border: none;