[x] Unsubscribing from newsletter - added as a tip to sign up from web
[x] Unsubscribing from a paid plan - How to cancel a subscription, changed from subsection to a section to make it more visible
[x] Deleting data (e.g. how long we retain the data and data restoration is possible) - this is mentioned separately for workspaces , projects , and now also in the new section about deleting an account
fix #408 TODO: