Update roadmap

TODO.org

@@ -10,7 +10,7 @@
   - [ ] Minimal resources management to avoid exhausting computer CPU and memory
 - User Interface
   - [X] Hide command prompts while running processes on Windows, and address file permissions errors
-  - [ ] Responsiveness issues during conversions (UI thread and background operations)
+  - [X] Responsiveness issues during conversions (UI thread and background operations)
   - [ ] There're probably too many redraw operations in the Desktop UI
   - [ ] Sorting in the conversion queue (file name, status, etc.)
   - [ ] Allow other operations during conversions (add more files, etc.)
@@ -19,7 +19,7 @@
   - [ ] Improve scrolling behavior during conversions ("smooth-scrolling")
 - [ ] Hardening
   - [ ] Review container execution options (podman v.s podman-remote, security options, etc.)
-  - [ ] Revisit Flatpak support requirements and =flatpak-spawn=
+  - [ ] Revisit Flatpak support, maybe it's best to leave that effort "the community" 
   - [ ] Review some of the code and read few security-related articles
 - [ ] Online Web Service
   - [ ] Evaluate [[https://github.com/tokio-rs/axum][axum]] as a replacement of [[https://github.com/actix/actix-web][actix_web]] ([[https://ordina-jworks.github.io/event-driven/2021/04/23/SSE-with-HTTP2.html#http11-vs-http2][HTTP2 support + SSE]] + browsers)