docs: remove redundant "successfully" and s/enter/Enter/
docs: remove redundant "successfully" and s/enter/Enter/

heartsucker/securedrop,conorsch/securedrop,conorsch/securedrop,heartsucker/securedrop,micahflee/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,conorsch/securedrop,heartsucker/securedrop,heartsucker/securedrop,garrettr/securedrop,ehartsuyker/securedrop,micahflee/securedrop,ehartsuyker/securedrop,garrettr/securedrop,garrettr/securedrop,ehartsuyker/securedrop,micahflee/securedrop,heartsucker/securedrop,garrettr/securedrop,conorsch/securedrop,ehartsuyker/securedrop,micahflee/securedrop,conorsch/securedrop