Agreements legal notice and Terms of Service section

Internal: Agreements is still a site-admin preview. The legal notice on a standard agreement's page and with an agreement's finished text now says that Magpie is not a law firm, is not acting as the member's lawyer, and does not check that the agreement suits their situation or can be enforced where they are, and links to the Terms of Service. The Terms of Service have a new section 7, Agreements (not legal advice, standard text provided as is, the member's responsibility), later sections are renumbered, and the limitation of liability covers agreements made using Agreements. The Agreements Help article has the same notice.