Add remove plugin functionality

[nonepork]

Adds the ability to remove marked plugins (or the plugin under the cursor) via a new keybinding. The changes include the implementation of the removal logic, integration with the UI, and updates to key mappings and hints.

• Added a new keybinding (d) for removing marked plugins or the plugin under the cursor in the UI, configurable via the remove_marked entry in config.lua.
• Implemented the remove and remove_marked functions in ui.lua to handle removal of plugins using vim.pack.del, with user notifications and state refresh. [1] [2]
• Registered the new keybinding in the UI keymap setup so users can trigger plugin removal from the interface.
• Updated the UI hints in render.lua to display the new "remove" action to users.

Also, sorry, should've use conventional commit titles, forgot this wasn't mine.
If the keybinds and implementation looks good I'll add documentation and stuff on another PR?