Add a shortcut to close the active/topmost dm

Literally the title, when getting @you're able to use CTRL+Alt+Shift+Arrow to jump to the ping, you can then respond and use CTRL+K to open the quick switcher and go jump to the previous chat to continue your conversation there.

However, unlike server @, direct messages create an icon that remains open even if you only needed to respond to it once, such as a user asking a question. Overtime this leads to the direct messages section filling up with direct messages that you may not have a use for however are too lazy to close.

(I am aware there's an X to close the direct message, but this requires taking your hand off of the keyboard, moving to the mouse, then moving the mouse to the X to click. Having a shortcut sidesteps that hassle and allows a more cohesive chat experience.)

At the moment I've worked around this by binding CTRL+D to click the section of the screen with an X via an AHK script, however it would be convenient to have this functionality work natively without having to install additional software.