add new posters and source code to download page

Makefile

@@ -5,7 +5,7 @@ SHARED_FILES := stallman.webp stallman_2024.webp favicon.ico \
 				moon.svg sun.svg narrow_light.svg narrow_dark.svg wide_light.svg wide_dark.svg lang_cz.svg lang_en.svg \
 				styles.css icons.css \
 				countdown.js theme.js lang.js
-STATIC_ASSETS := jetbrains_mono.woff2
+STATIC_ASSETS := jetbrains_mono.woff2 poster_cz.png poster_en.png
 SEARCH_REPLACE := lib/search_and_replace/target/release/search_and_replace
 COMPONENTS := head.html header.html nav.html footer.html
 
@@ -72,6 +72,10 @@ dst/%.webp: images/%.jpg
 	@mkdir -p $(@D)
 	magick $< $@
 
+dst/%.png: images/%.png
+	@mkdir -p $(@D)
+	ln -f $< $@
+
 dst/%.svg: icons/%.svg
 	@mkdir -p $(@D)
 	ln -f $< $@