Add specific antisemitism clause

[pbiggar]

Antisemitism should not be tolerated in this space or any other. We must be very clear in the CoC that antisemitism is not acceptable, and will result in removal from the community.

Since our advocacy focuses on the actions of the state of Israel towards the people of Palestine, and not of Jewish people in general (many of whom have long been pro-Palestinian activists, such as Jewish Voices for Peace), we must be aware as a community of the distinction between the Jewish people and the state of Israel, and reflect this awareness in the language we use throughout the community.