[snap] add desktop launcher, fixes #1662

CHANGES.md

@@ -3,6 +3,7 @@
 # Changes #
 
 * @dev (????-??-??)
+  * Fixed appearance of LSe desktop icon [#1662]
   * Update controlled buffer behavior to pass U and E inputs while enabled [#1642]
   * Introduced user-defined color for components.
   * Made component icons more uniform.

snap/gui/logisim-evolution.desktop

@@ -0,0 +1,12 @@
+[Desktop Entry]
+Name=Logisim-evolution
+Comment=Logisim-evolution is educational software for designing and simulating digital logic circuits.
+GenericName=Digital logic design tool and simulator
+Exec=logisim-evolution %f
+Icon=${SNAP}/meta/gui/logisim-icon-128.png
+Type=Application
+StartupNotify=false
+Categories=Electronics
+MimeType=application/x-logisim-circuit;
+Actions=new-empty-window;
+Keywords=circuits;simulation;logic;HDL;chronogram;