Actually, the gallery macro supports wiki syntax so we just need to mark it as such (thanks Michael Hamann for the suggestion).
To do it we should probably change the constructor to:
public GalleryMacro() { super("Gallery", DESCRIPTION, new DefaultContentDescriptor(CONTENT_DESCRIPTION, true, Block.LIST_BLOCK_TYPE), GalleryMacroParameters.class); setDefaultCategories(Set.of(DEFAULT_CATEGORY_LAYOUT)); }
But we need to check the consequences on the wysywig editor.