Minor corrections to sorted arrays documentation.

Minor corrections to sorted arrays documentation.

Mention that Remove() uses binary search for sorted arrays so the item removed
by it is not necessarily the first one. Also correct documentation of Index()
for sorted arrays which was incorrectly the same as for the normal kind.

Closes #11233.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62046 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775