Clarify sign in and sign up pages

One of the biggest feedback we receive from the end users after implementing few live instances of Decidim is the clarity of the sign in and sign up processes. Many find these pages confusing which causes unnecessary support requests to the support organizations. We believe the both processes (login and register) could be clarified with easy and small modifications: - Move the OAuth login methods above the Decidim's own forms - Hide the system's own forms by default - Make the forms appear after clicking a link We feel that people are usually familiar with the logos of the social login methods and therefore it would make sense to make these more visible. More you ask for the user to do (filling the forms), the less users you will have. In case there is some proper argument for keeping the forms visible by default, we would suggest to make this at least configurable.