poss minor doc error + minor doc suggestion

*Poss doc error*

Page: https://www.tcl.tk/man/tcl9.0/TclCmd/define.html#M55
This is the examples section.
In the example that begins with the line:

  oo::class create DBTable {

The interactive output reported at the end looks slightly wrong. For
example, it shows:

    set u1 [Users insert "username=abc"]
        → DB: create row from ::Users matching username=abc

but I was expecting:

    set u1 [Users insert "username=abc"]
        → DB: create row in ::Users matching username=abc

This also applies to the 'set u2' example that follows.

*Doc suggestion*

Page: https://www.tcl.tk/man/tcl9.0/TclCmd/configurable.html#M5
This is the description section.

I suggest adding a sentence something like:

    Note that oo::configurable classes can only be mixed in (using
`mixin`) with _other_ oo::configurable classes, not with plain oo::class
classes.

The reason for suggesting this is that I tried mixing in an oo::class with
an oo::configurable and got a very confusing "unknown method "configure":"
error message.