Update api.mdx
Update api.mdx

doc fix  - dont esscape $ for VAGRANT_CLOUD_TOKEN env VAR
chrisroberts/vagrant,chrisroberts/vagrant,chrisroberts/vagrant,sni/vagrant,mitchellh/vagrant,chrisroberts/vagrant,sni/vagrant,marxarelli/vagrant,marxarelli/vagrant,marxarelli/vagrant,sni/vagrant,sni/vagrant,marxarelli/vagrant,mitchellh/vagrant,mitchellh/vagrant,mitchellh/vagrant