Where did the AppImage of polar-bookshelf go? #4186

Hi @burtonator, thank you for this entry in the AppImage catalog!

Our monthly check found that data/polar-bookshelf points to https://github.com/burtonator/polar-bookshelf/releases/download/v1.0.14/polar-bookshelf-1.0.14-x86_64.AppImage, which no longer seems to be available (download URL returned 404 (https://github.com/burtonator/polar-bookshelf/releases/download/v1.0.14/polar-bookshelf-1.0.14-x86_64.AppImage)).

Could you help us fix this?

• If the AppImage moved, please open a pull request updating data/polar-bookshelf with the new download or repository URL. You can edit it directly here: https://github.com/AppImage/appimage.github.io/edit/master/data/polar-bookshelf
• If the project was discontinued or no longer publishes an AppImage, please let us know by replying here, we are interested in the reasons.

Sorry if this entry has been broken for a while, and thanks again for contributing it!