[docs] Add a note about AppImage desktop integration (#2110)

docs/docs/photos/faq/security-and-privacy.md

@@ -98,4 +98,5 @@ Note that both Ente photos and Ente auth data will be deleted when you delete
 your account (irrespective of which app you delete it from) since both photos
 and auth use the same underlying account.
 
-To know details of how your data is deleted, including when you delete your account, please see https://ente.io/blog/how-ente-deletes-data/.
+To know details of how your data is deleted, including when you delete your
+account, please see https://ente.io/blog/how-ente-deletes-data/.

docs/docs/photos/troubleshooting/desktop-install/index.md

@@ -9,6 +9,9 @@ The latest version of the Ente Photos desktop app can be downloaded from
 [ente.io/download](https://ente.io/download). If you're having trouble, please
 see if any of the following cases apply.
 
+-   [Windows](#windows)
+-   [Linux](#linux)
+
 ## Windows
 
 If the app stops with an "A JavaScript error occurred in the main process - The
@@ -22,7 +25,26 @@ This is what the error looks like:
 You can install the Microsoft VC++ redistributable runtime from here:<br/>
 https://learn.microsoft.com/en-us/cpp/windows/latest-supported-vc-redist?view=msvc-170#latest-microsoft-visual-c-redistributable-version
 
-## AppImages on ARM64 Linux
+## Linux
+
+### AppImage desktop integration
+
+AppImages are not fully standalone, and they require additional steps to enable
+full "desktop integration":
+
+-   Showing the app icon,
+-   Surfacing the app in the list of installed apps,
+-   Handling redirection after passkey verification.
+
+All the ways of enabling AppImage desktop integration are mentioned in
+[AppImage documentation](https://docs.appimage.org/user-guide/run-appimages.html#integrating-appimages-into-the-desktop).
+
+For example, you can download the
+[appimaged](https://github.com/probonopd/go-appimage/releases) AppImage, run it,
+and then download the Ente Photos AppImage into your `~/Downloads` folder.
+_appimaged_ will then pick it up automatically.
+
+### AppImages on ARM64
 
 If you're on an ARM64 machine running Linux, and the AppImages doesn't do
 anything when you run it, you will need to run the following command on your
@@ -42,7 +64,7 @@ details, see the following upstream issues:
 -   libz.so: cannot open shared object file with Ubuntu arm64 -
     [electron-userland/electron-builder/issues/7835](https://github.com/electron-userland/electron-builder/issues/7835)
 
-## AppImage says it requires FUSE
+### AppImage says it requires FUSE
 
 See
 [docs.appimage.org](https://docs.appimage.org/user-guide/troubleshooting/fuse.html#the-appimage-tells-me-it-needs-fuse-to-run).
@@ -53,7 +75,7 @@ tl;dr; for example, on Ubuntu,
 sudo apt install libfuse2
 ```
 
-## Linux SUID error
+### Linux SUID error
 
 On some Linux distributions, if you run the AppImage from the CLI, it might fail
 with the following error: