Update buy.html

[martcpp]

Added strong and red colour the thirds party system moonpay for easy seeing by users to avoid misunderstanding

[martcpp]

This will make it noticable by user so they understand that using moonpay is third-party

[martcpp]

This has been major issue to buyer after they had done thier transaction believing it from bitcoin with knowing it from a third party

[martcpp]

These will reduce fraud on third party

[martcpp]

This will save customer the stress to know it s third party service