Allow config.linking to have extra attributes set (for trainer) (#15)

Author: mart-r

medcat-v2/medcat/config/config.py

@@ -166,6 +166,7 @@ class NLPConfig(SerialisableBaseModel):
 
     # NOTE: this will allow for more config entries
     #       since we don't know what other implementations may require
+
     class Config:
         extra = 'allow'
         validate_assignment = True
@@ -358,6 +359,9 @@ class Linking(ComponentConfig):
     and learning rate for type contexts.
     """
 
+    class Config:
+        extra = 'allow'
+
 
 class Preprocessing(SerialisableBaseModel):
     """The preprocessing part of the config"""