Clarify exitcode docs

Author: cmoog

exec.go

@@ -30,7 +30,7 @@ type Process interface {
 	Stderr() io.Reader
 	// Resize resizes the TTY if a TTY is enabled.
 	Resize(ctx context.Context, rows, cols uint16) error
-	// Wait returns ExitError when the command terminates.
+	// Wait returns ExitError when the command terminates with a non-zero exit code.
 	Wait() error
 	// Close terminates the process and underlying connection(s).
 	// It must be called otherwise a connection or process may leak.

internal/proto/README.md

@@ -79,7 +79,7 @@ and a body follows after a newline character.
 This is the last message sent by the server.
 
 ```json
-{ "type": "exit_code", "code": 255 }
+{ "type": "exit_code", "exit_code": 255 }
 ```
 
 A normal closure follows.