[coc-tf] Updating the draft announcement

Dear TF, When we met yesterday we agreed to encourage people to provide feedback on the draft on the RIPE Discussion List but to provide the opportunity for people to provide feedback in private to us or the RIPE Chair Team. I have updated the draft announcement to make this clear. The new text is highlighted in orange: https://docs.google.com/document/d/11_yFznrdw6TAs40t2I8edRUjfWGho10q7f99gFoH... I'd be grateful if you could review the text and make suggestions for any improvements needed. Many thanks, Leo