chore: improve claude prompt

Author: lpatiny

CLAUDE.md

@@ -2,7 +2,7 @@ We are creating svg icons for scientific applications.
 
 The icons are 1000x1000 by default (viewBox="0 0 1000 1000").
 
-You need to create new icons and take care they match current design.
+You need to create new icons and take care they match current design. When receiving a request check that it is not a mistake and that a similar icon already exists !
 
 When you create a new icon you need to render it as an image to evaluate the quality and then improve the SVG. Use `rsvg-convert` to render to PNG.