- Closes #18868 ## Summary This PR introduces a new slash command `/selection` to enhance the usability of the assistant's quote selection feature. ## Changes Made 1. Extracted a function from the `assistant: quote selection` action to find the selected text and format it as an assistant section. 2. Created a new slash command `/selection` that utilizes the extracted function to achieve the same effect as the existing `assistant: quote selection` action. 3. Updated the documentation to include information about the new `/selection` slash command. Release Notes: - Moved the text selection action to a slash command (`/selection`) in the assistant panel --------- Co-authored-by: Danilo Leal <67129314+danilo-leal@users.noreply.github.com> Co-authored-by: Bennet Bo Fenner <bennet@zed.dev>