Expand the rule set

[lcreteig]

The ContextD triggers (available at this link) might need to be supplemented with more rules. Probably good to put these in their own .json file, so we can easily swap rule-sets in and out?

• More (negation) triggers from other sources, e.g.
  • the default rules that come with medspacy. Will have to be translated.
  • the rules in the dutchclinicalnegation project from CLiPS.
  • the rules from another implementation of ConText. Will have to be translated.
• More negation triggers from our own experience (e.g. Argus or SLE projects)
• Negation triggers from Add to context_rules #19 (comment)