Update experimental PDB Viewer with WebGPU

Author: GitHubDragonFly

viewers/templates/PDB WebGPU.html

@@ -334,7 +334,7 @@
         <button title="URL of the remote 3D model" id="btn_url" onclick="show_url();" style="background-color: transparent; min-width: 34px;">URL</button>
         <input type="file" title="Browse Local Files" id="file_input" onchange="init();" accept=".pdb, .zip" />
         <label for="file_image_input" title="Background Image" style="color: #553801;">BGND</label>
-        <input type="file" title="Background Image" id="file_image_input" accept=".exr, .hdr, image/png, image/jpeg, image/bmp, image/gif, image/svg+xml, image/webp" onchange="set_scene_image();" disabled />
+        <input type="file" title="Background Image" id="file_image_input" accept=".exr, .hdr, .ktx2, image/avif, image/bmp, image/gif, image/jpeg, image/png, image/svg+xml, image/webp" onchange="set_scene_image();" disabled />
         <button title="Set Background Image Y-Flip" id="btn_bg_flip" onclick="set_bg_flip();" style="background-color: transparent; color: blue;" disabled>Y</button>
         <button title="Toggle Equirectangular Background" id="btn_equi" onclick="set_equi();" style="background-color: transparent; color: blue; min-width: 25px;" disabled>Eq</button>
         <button title="Toggle Gradient Color Background" id="btn_bgnd_linear_gradient" onclick="set_bgnd_linear_gradient();" style="background-color: transparent; color: blue;" disabled>G</button>