Added myself to MAINTAINERS

[Paolo Carlini]

Ed Smith-Rowland wrote:
> I added myself (Edward Smith-Rowland) to MAINTAINERS (Write After
> Approval).
>
> I work on libstdc++.
>
> Thanks all, especially my mentors Paolo Carlini and Benjamin Kosnik ;-),
The first one thanks and recommends:

1- Not sending patches to gcc@
2- Not sending ChangeLog entries as part of the diff
3- Not sending generated files as part of the diff
4- Posting in any case the right patch ;)

Good work,
Paolo.