Add ordinal terms to overrides csv, docs and cheatsheet

[pokey]

Terms

• "first"
• "last"
• "previous"
• "next"
• "every"
• "backward"
• ordinals (just for docs and cheatsheet; not csv)

Steps

• Add <scope> to legend, linking it to scopes section of cheatsheet
• cheatsheet
• docs
• csvs

Notes

• They should go in modifiers.csv
• In cheatsheet they go in Modifiers section, with a <scope> suffix

Originally posted by @pokey in #960 (comment)