Allow Tricordrazine to Heal Minor Accidental Exposures (#1840)

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# Description

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As requested in Goob:
https://discord.com/channels/1323488536501944350/1323488538750353442/1343047906114011167
this allows Tricordrazine to heal _very minor_ amounts of radiation
poisoning. The use case: I walked past a Borg with a micro-RTG and the
medibot won't stop bugging me because it doesn't know it can't help.
With this change it _can_ help, but it's really only viable for small
amounts.
Ordinarily, in these small amounts of damage (10-12 tops), it was a
hassle to make appropriate radiation medicine for; a lot of effort for
only a tiny problem. This apparently caused annoyance, and this change
will both make Tricordrazine a tiny bit more useful and lessen the
aforementioned problem.

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# Changelog

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:cl:
- tweak: Tweaked Tricordrazine to heal MINOR amounts of radiation
damage. This includes Medibots. If it's more than a teeny tiny amount,
go to medical! This also alleviates the issue where the medibot keeps
pestering you about the 0.1 rad damage because it thinks it can heal it,
while the medicine it'll inject (before this change) didn't actually do
anything.

Resources/Prototypes/Reagents/medicine.yml

@@ -781,6 +781,7 @@
             Brute: -1
           types:
             Poison: -0.5 ##Should be about what it was when it healed the toxin group
+            Radiation: -0.15 ##Should really only heal minor accidental exposures
             Heat: -0.5
             Shock: -0.5
             Cold: -0.5 # Was .33, Buffed due to limb damage changes