General Minor Enhancements Part 3

Continuing from #65

- [ ] in the doPost() function, add better feedback when something is 'loading' (like a global loading symbol or loading bar which runs across the screen)
- [ ] Manually added mod option downloads are always added *after* the normal options. Therefore their priority levels can't be in-between the existing downloads, only can come after them. Not sure if this is the desired behavior, or if there is even a case where you would want this. But the behavior is confusing at the moment as in the JSON it's called "priority' for both priorities, even though they are different priorities.
- [ ] Add option to download only (stop after downloads complete)
- [ ] Add "open downloads folder" / "open installer folder" button
- [ ] Add free disk space check (Not implemented on mac, but otherwise DONE)
- [ ] Fix duplicate mod size (probably remove top mod size warning)
- [ ] On chrome, index page images look blurry due to chrome's resize algorithm (as compared to firefox). Consider pre-resizing the images to their native res or displaying them at their native res
- [ ] **Automatically saved output log at end of install includes `output.txt` which may be misleading as this is probably a leftover from the previous install, rather than from when the user ran the game**

Untersuchen Sie die doPost()-Funktion für das Laden von Feedback, die Logik für die Priorität von Mod-Downloads und die UI-Komponenten für neue Schaltflächen wie 'Downloads-Ordner öffnen'. Prüfen Sie, wie Mod-Größen berechnet und angezeigt werden, und inspizieren Sie das Bild-Rendering auf der Index-Seite. Der Mechanismus zum Speichern von Ausgabelogs muss überprüft werden, um das Einbeziehen von übriggebliebenen Dateien zu vermeiden.

Vom Indexierungsmodell aus dem Issue-Text verfasst.