Merge pull request #384 from storytold/feat/297-image-sequences

Import: image sequences with a Sequence option, ranges, folders and missing frames (#297)

# Conflicts:
#	docs/parity.md

crates/engine/src/render_queue.rs

@@ -624,8 +624,8 @@ impl Session {
         if item.post_render.is_none() {
             return Ok(None);
         }
-        let importer = self.importer.clone().ok_or("media import is not available in this build")?;
-        let footage = importer.probe(path)?;
+        // A rendered image sequence's first file brings the sequence.
+        let footage = self.probe_footage(path)?;
         if item.post_render == PostRenderAction::SetProxy {
             crate::commands::proxy_set(self, item.comp, footage).map_err(|e| e.to_string())?;
             self.toast(format!("Proxy set from {path}"));