Clarify post privacy warning

Mastodon is not an alternative, it is a solution

This month I traveled to Cambridge, Massachusetts with my friends and attended LibrePlanet 2017. At the talk *Technology for direct actions*, Andrew Seeder pointed out that we often call free software an "alternative" to what exists. But an alternative is something that is mostly similar, and differentiated by preference rather than need. For instance, a trackball is an alternative to a mouse, but a jail is not an alternative to a bedroom. Andrew suggested that we start looking at free software as "solutions" rather than alternatives. So I propose boldly proclaiming that Mastodon is not an alternative to Twitter, but rather a solution to it.

Needs to be a separate task with no locking

Update amaroq name

I was informed that the current warning if you @ a remote server in a private post is inadequate. These are suggested changes to better inform users.

Thanks garg

Privacy descriptions were very difficult to reason. This is the minimal level of color contrast to be WCAG AA compliant.

Descriptions of differences between scope are more clear

🔧 S3 protocol  from ENV

add support for reading S3 protocol from ENV
also add S3_HOSTNAME in .env.production.sample