fix: update app image (openfoodfacts#2288)

* fix: update app image

* fix: update app image

* fix: update app image for dark mode

* fix: update app image for dark mode

README.md

@@ -1,4 +1,8 @@
-<img height='175' src="https://en.blog.openfoodfacts.org/images/EXE_LOGO_OFF_RVB_Plan_de_travail_1_copie_0_t.jpg" align="left" hspace="1" vspace="1">
+<picture>
+  <source media="(prefers-color-scheme: dark)" srcset="https://static.openfoodfacts.org/images/logos/off-logo-horizontal-dark.svg">
+  <source media="(prefers-color-scheme: light)" srcset="https://static.openfoodfacts.org/images/logos/off-logo-horizontal-light.svg">
+  <img height="100" src="https://static.openfoodfacts.org/images/logos/off-logo-horizontal-light.svg">
+</picture>
 
 # Open Food Facts - Codename: "Smooth App"
 [![SmoothApp Post-Submit Tests](https://github.com/openfoodfacts/smooth-app/actions/workflows/postsubmit.yml/badge.svg)](https://github.com/openfoodfacts/smooth-app/actions/workflows/postsubmit.yml)