Adapt to flatpak (#526)

* Restrict Flatpak access a little bit more

* Adapt README.md

README.md

@@ -6,18 +6,32 @@ Community:
 If you like, you are kindly invited to join the [Discord channel](https://discord.gg/HAfKkJz) and 
 the [Google group](https://groups.google.com/group/treesheets) for discussion.
 
+Installation:
+-------------
+
+### Windows/Ubuntu LTS/MacOS users
+
+Pre-built binaries are available at the
+[Release section](https://github.com/aardappel/treesheets/releases). 
+
+Please note that the Linux builds provided are built and only compatible with `ubuntu-latest` used by [GitHub Actions Runner](https://github.com/actions/runner-images). 
+
+### Flatpak (Linux) users
+
+If you use Flatpak, you can install [TreeSheets from Flathub](https://flathub.org/apps/com.strlen.TreeSheets).
+
 Repository:
 -----------
-
 This repository contains all the files needed to build TreeSheets for various platforms.
-If instead you just want to USE TreeSheets, you may be better off with the binaries available in the
-[Release section](https://github.com/aardappel/treesheets/releases). Please note that the Linux builds are built
-and only compatible with `ubuntu-latest` used by [GitHub Actions Runner](https://github.com/actions/runner-images).
+
+### License
 
 TreeSheets has been licensed under the ZLIB license (see ZLIB_LICENSE.txt).
 
 ![Workflow status](https://github.com/aardappel/treesheets/actions/workflows/build.yml/badge.svg)
 
+### Structure
+
 `src` contains all source code. The code is dense, terse, and with few comments, typical for a codebase that was never
 intended to be used by more than one person (me). On the positive side, you'll find the code very small and simple,
 with all functionality easy to find and only in one place (no copy pasting or over-engineering). Enjoy.

linux/com.strlen.TreeSheets.yml

@@ -7,7 +7,7 @@ finish-args:
   - --socket=wayland
   - --socket=fallback-x11
   - --share=ipc
-  - --device=all
+  - --device=dri
   - --filesystem=home
 cleanup:
   - /include