flatpak: add page (#2316)

pages/linux/flatpak.md

@@ -0,0 +1,27 @@
+# flatpak
+
+> Build, install and run flatpak applications and runtimes.
+
+- Run an installed application:
+
+`flatpak run {{name}}`
+
+- Install an application from a remote source:
+
+`flatpak install {{remote}} {{name}}`
+
+- List all installed applications and runtimes:
+
+`flatpak list`
+
+- Update all installed applications and runtimes:
+
+`flatpak update`
+
+- Add a remote source:
+
+`flatpak remote-add --if-not-exists {{remote-name}} {{remote-url}}`
+
+- List all configured remote sources:
+
+`flatpak remote-list`