Update CHANGELOG.md
Update CHANGELOG.md

Turns out it has to be on `master` so we can link to it properly.
mattermost/desktop,yuya-oc/desktop,yuya-oc/desktop,yuya-oc/desktop,St-Ex/desktop,mattermost/desktop,mattermost/desktop,yuya-oc/electron-mattermost,jnugh/desktop,yuya-oc/electron-mattermost,mattermost/desktop,jnugh/desktop,yuya-oc/electron-mattermost,St-Ex/desktop,St-Ex/desktop,mattermost/desktop,jnugh/desktop