Changes at "Improve the Privacy Policy consent textarea with a summary"

Ref. GDPR03

Is your feature request related to a problem? Please describe.
As a visitor when registering in Decidim I see a wall of text on the Terms of Service section that’s difficult to read.

Describe the solution you’d like

We should explain better the privacy policy summary, so it’s more understandable for visitors. Right now what we have is a textarea with all the contents of the Terms of Use page.

For instance, on the Decidim Barcelona case, this is the current behavior:

We should improve this page with a summary explaining all the summary and more relevant information:

In the case where this summary field isn’t filled, then it’ll show all the contents, but at least with styling and allowing scrolling it.

Describe alternatives you’ve considered

To have this information in yet another modal

Additional context
This is related to GDPR

From the Metadecidim proposal (External link):

The text is curently displayed in bunk on the /users/signup which makes it hardly readable.

Related also to this Metadecidim bug report (External link)

Does this issue could impact on users private data?
This is an improvement for explaining to the participant how the platform admins handle their data.

Acceptance criteria

• As an administrator, I can add this summary on the Terms of Services page
• As a visitor, I can see the summary on the sign-up page
• As a visitor, I can see the summary on the Terms of Services page
• Given that I’m a visitor
  And this summary isn’t filled,
  When I go to the registration page, I can see the full page with scroll and styles in this page