README: Add link to mailing list.
README: Add link to mailing list.

openpandora/meta-openpandora-vendor,kraj/meta-openpandora,kraj/meta-openpandora,openpandora/meta-openpandora-vendor,openpandora/meta-openpandora-vendor,openpandora/meta-openpandora,kraj/meta-openpandora,openpandora/meta-openpandora-vendor,kraj/meta-openpandora,openpandora/meta-openpandora,openpandora/meta-openpandora,openpandora/meta-openpandora-vendor,openpandora/meta-openpandora