doc: remove wrong sentence
see
@@ -83,7 +83,6 @@ kdb cp -r user/tests/cp/examples/kdb-cp/key user/tests/cp/examples/kdb-cp/cpkey
# To copy keys below an existing key:
kdb cp -r user/tests/cp/examples/kdb-cp/another user/tests/cp/examples/kdb-cp/another/key
#>
-# Note that in this example, all keys in the `another` directory will be copied below `key` **except** `key`.
kdb rm -r user/tests/cp/examples/kdb-cp/
```
