Add list context to query traits

Author: JordonPhillips

smithy-docgen-core/src/main/java/software/amazon/smithy/docgen/core/interceptors/HttpQueryInterceptor.java

@@ -30,9 +30,13 @@ protected ShapeId getTraitId() {
 
     @Override
     void write(DocWriter writer, String previousText, ProtocolSection section, HttpQueryTrait trait) {
+        var target = section.context().model().expectShape(section.shape().asMemberShape().get().getTarget());
         writer.putContext("param", trait.getValue());
+        writer.putContext("list", target.isListShape());
         writer.write("""
-                This is bound to the HTTP query parameter ${param:`}.
+                This is bound to the HTTP query parameter ${param:`}.${?list} Each element in \
+                the list is represented by its own key-value pair, each instance using the \
+                same key.${/list}
 
                 $L""", previousText);
     }

smithy-docgen-core/src/main/java/software/amazon/smithy/docgen/core/interceptors/HttpQueryParamsInterceptor.java

@@ -7,6 +7,7 @@
 
 import software.amazon.smithy.docgen.core.sections.ProtocolSection;
 import software.amazon.smithy.docgen.core.writers.DocWriter;
+import software.amazon.smithy.model.shapes.MapShape;
 import software.amazon.smithy.model.shapes.ShapeId;
 import software.amazon.smithy.model.traits.HttpQueryParamsTrait;
 import software.amazon.smithy.utils.SmithyInternalApi;
@@ -30,8 +31,14 @@ protected ShapeId getTraitId() {
 
     @Override
     void write(DocWriter writer, String previousText, ProtocolSection section, HttpQueryParamsTrait trait) {
+        var memberTarget = section.shape().asMemberShape().get().getTarget();
+        var map = section.context().model().expectShape(memberTarget, MapShape.class);
+        var valueTarget = section.context().model().expectShape(map.getValue().getTarget());
+        writer.putContext("list", valueTarget.isListShape());
         writer.write("""
-                Each pair in this map represents an HTTP query parameter.
+                Each pair in this map represents an HTTP query parameter.${?list} Each element in \
+                the value lists is represented by its own key-value pair, each instance using the \
+                same key.${/list}
 
                 $L""", previousText);
     }