Clarify wording of draft 1.0.0 release notes, fix typos.
Clarify wording of draft 1.0.0 release notes, fix typos.

mike-jumper/incubator-guacamole-website,mike-jumper/incubator-guacamole-website,mike-jumper/incubator-guacamole-website,mike-jumper/incubator-guacamole-website,mike-jumper/incubator-guacamole-website