general improvements to several role pages, adds several placeholder and complete pages.

[PerfectTangent]

This PR:

• adds a boxstation page.
• adds a square station page.
• adds a centcom intern page.
• adds a security items page.
• adds a medical items page.
• adds a general items page.
• adds an engineering items page.
• adds a science items page.
• adds a placeholder page for player species.
• adds a redshield page.
• fixes some wording in the SOP page and adds the references to the AI now that it is a playable role.
• fixes really weird formatting in the Paramedic page and also trimmed it for length.
• fixed many typos, added some footnotes relating to SOP, and cut some of the indulgent prose of the HoS's page.
• edited the formatting of the Clown page.
• edited the High Risk Items page so it's less opinionated and stays to the point. Also added the hypospray to the list and corrected the ambiguous information on the ablative trenchcoat.
• updated a lot of the now irrelevant information in the Engineer page so that it is more relevant to modern Unitystation.
• closes #58
• closes #61
• closes #62
• closes #63
• closes #65
• makes progress on #22

[PerfectTangent]

several of the added pages are completely barebones, with nothing written in them. More work will have to be done, but it is easier for people to see what is missing with placeholder pages.

Self mergerino.