Update suggested keybindings in README.md

Author: intitni

README.md

@@ -176,6 +176,8 @@ A [recommended setup](https://github.com/intitni/CopilotForXcode/issues/14) that
 | Reject Suggestion | `⌥{` |
 | Next Suggestion | `⌥>` |
 | Previous Suggestion | `⌥<` |
+| Chat with Selection | `⌥"` |
+| Explain Selection | `⌥\|` |
 
 Essentially using `⌥⇧` as the "access" key combination for all bindings.