Added triffid weakpoints and weakpoint proficiencies

[PatrikLundell]

Summary

None

Purpose of change

Provide triffids with weakpoints, weakpoint proficiencies, and dissection snippets.

Describe the solution

Add the corresponding JSON entries.

Describe alternatives you've considered

Testing

• Debug spawned a triffid.
• Fought it once and checked that the triffid basic proficiency showed up.
• Debug mastered the proficiency.
• Fought it further to verify the advanced proficiency showed up.
• Debug killed it and verified the expected set of dissection proficiencies showed up when selecting butcher/dissection.
• Debug spawned another triffid (no reason other than having forgotten to check weakpoint messages on the first one).
• Fought it until a couple of weakpoint messages had been shown.
• Debug killed it.
• Dissected it to verify a dissection snippet appeared.

Additional context

[github-actions]

Spell checker encountered unrecognized words in the in-game text added in this pull request. See below for details.

Click to expand

• At the top of the creature you find what you assume is a brain, although it seems to employ quadrilateral symmetry and thus is shaped and organized completely differently from that of terrestial versions.

This alert is automatically generated. You can simply disregard if this is inaccurate, or (optionally) you can also add the new words to tools/spell_checker/dictionary.txt so they will not trigger an alert next time.