Remove feature "Set as space description"

[AlexAndBear]

Describe the bug

The process for updating space descriptions via set as readme action can be confusing for users. When they choose to set a file as the space description, it copies the markdown content into the .space folder and replaces the readme.md. However, this behavior might lead users to believe they can modify the original file directly, which isn’t the case.

To enhance clarity, we should remove the “Set as Description” action altogether. This will eliminate confusion and ensure users follow the correct process for updating space descriptions via edit description action .