Merge branch 'feature/config-endpoint' into 'master'

config/config.exs

config/test.exs

js/src/components/NavBar.vue

js/src/graphql/config.ts

js/src/types/config.model.ts

js/src/views/User/Login.vue

lib/mobilizon/common-config.ex

lib/mobilizon/users/user.ex

lib/mobilizon_web/resolvers/config.ex

lib/mobilizon_web/resolvers/user.ex

lib/mobilizon_web/schema.ex

lib/mobilizon_web/schema/config.ex

test/mobilizon_web/resolvers/config_resolver_test.exs

test/mobilizon_web/resolvers/user_resolver_test.exs