Adding a button to see an instance's privacy policy in the sidebar

**Is your feature request related to a problem? Please describe.**

As a user I would like to see an instance's privacy policy to see how my data is handled on an instance

**Describe the solution you'd like**

A button in the sidebar which I can tap to display that particular instance's privacy policy

**Describe alternatives you've considered**

Right now the only way to see an instance privacy policy is through a browser.