vifm: Add markdown icon to quarto files

.qmd files now also display the markdown symbol.

terminal/.config/vifm/favicons.vifm

@@ -39,7 +39,7 @@ set classify+='λ  ::*.ml,,*.mli::,
             \   ::*.scss::,
             \   ::*.py,,*.pyc,,*.pyd,,*.pyo::,
             \   ::*.php::,
-            \   ::*.markdown,,*.md::,
+            \   ::*.markdown,,*.md,,*.qmd::,
             \   ::*.json::,
             \   ::*.js::,
             \   ::*.bmp,,*.gif,,*.ico,,*.jpeg,,*.jpg,,*.png,,*.svg,,*.svgz,,*.tga,,*.tiff,,*.xmb,,*.xcf,,*.xpm,,*.xspf,,*.xwd,,*.cr2,,*.dng,,*.3fr,,*.ari,,*.arw,,*.bay,,*.crw,,*.cr3,,*.cap,,*.data,,*.dcs,,*.dcr,,*.drf,,*.eip,,*.erf,,*.fff,,*.gpr,,*.iiq,,*.k25,,*.kdc,,*.mdc,,*.mef,,*.mos,,*.mrw,,*.obm,,*.orf,,*.pef,,*.ptx,,*.pxn,,*.r3d,,*.raf,,*.raw,,*.rwl,,*.rw2,,*.rwz,,*.sr2,,*.srf,,*.srw,,*.tif,,*.x3f,,*.webp,,*.avif,,*.jxl::,