[Linux] desktop file is lacking a Categories= entry

[probonopd]

The desktop file is lacking a Categories= entry in the *.desktop file.

According to the menu spec,

By including one of the Main Categories in an application's desktop entry file, the application will be ensured that it will show up in a section of the application menu dedicated to this category. If multiple Main Categories are included in a single desktop entry file, the entry may appear more than once in the menu.

Hence, please add at least one of the following in the Categories= key.

Main Category	Description	Notes
AudioVideo	Application for presenting, creating, or processing multimedia (audio/video)
Audio	An audio application	Desktop entry must include AudioVideo as well
Video	A video application	Desktop entry must include AudioVideo as well
Development	An application for development
Education	Educational software
Game	A game
Graphics	Application for viewing, creating, or processing graphics
Network	Network application such as a web browser
Office	An office type application
Science	Scientific software
Settings	Settings applications	Entries may appear in a separate menu or as part of a "Control Center"
System	System application, "System Tools" such as say a log viewer or network monitor
Utility	Small utility application, "Accessories"

In addition, you could specify one or more from the longer list of Additional Categories.

Please test the result with desktop-file-validate and make sure it passes.

electron-builder offers native support for this since v19.22.1.

Reference: AppImage/appimage.github.io#2