[FR]: Add Global Appmenu feature enable for kde desktop environment.

### Description

Hi Appflowy team , first thanks for creating this amazing open source note management application , I am currently running fedora linux 36 with kde spin and it has been a very good responsive experience for me , there can be imporovement too-

- It can have a scale option where user can have its choice to scale the app with option of - 100% , 125% or any other.

- Can you add Global Appmenu support for the application.

- You can just provide AppImage of appflowy application as it is very easy to maintain.

- Dark mode can also be improved.


### Impact

1. Adding scaling factor can help many users with bigger resolution to adjust the app according to their need.
2. As Distro independent packages and applications are the new trend in the linux community it would be great to have it in the format of AppImage.

### Additional Context

_No response_