Add user code of conduct agreement and general purpose statements

[zealsprince]

Users using the site should be required to agree to terms around what is accepted on the platform. Examples of this could be the following points.

• Images should be posted in good faith that all those shown in said images are aware of them being posted
• Images should not show people in a negative way

These terms should also be shown to users when they sign-up other users, as to confirm they are aware the responsibility and actions of those they invite fall on them as well.

[dolanske]

Can add something like on quotes if someone writes me the language for it.