Properly Populate Terms of Service and Privacy Policy Pages

[ribose-jeffreylau]

After #139 is "fixed", it is time to populate these pages with proper content.

[ribose-jeffreylau]

Do we need the expertise from the legal team?

cc: @ronaldtse

[ronaldtse]

Let’s apply the same content first and we’ll do the legal changes. Thanks!

[ribose-jeffreylau]

Same content applied (but removed references to About page since there's none in open.ribose.com).