Updated change log

Author: kmvanbrunt

CHANGELOG.md

@@ -8,7 +8,8 @@
     methods allow developers to enable custom tab completion behavior for a given parser by using a custom
     `ArgparseCompleter`-based class.
   * Added `ap_completer_type` keyword arg to `Cmd2ArgumentParser.__init__()` which saves a call
-    to `set_ap_completer_type()`. This keyword will also work in `add_parser()` when creating subcommands.
+    to `set_ap_completer_type()`. This keyword will also work with `add_parser()` when creating subcommands
+    if the base command's parser is a `Cmd2ArgumentParser`.
   * New function `register_argparse_argument_parameter()` allows developers to specify custom 
     parameters to be passed to the argparse parser's `add_argument()` method. These parameters will
     become accessible in the resulting argparse Action object when modifying `ArgparseCompleter` behavior.