Initial draft of StructDecl node descriptions

Author: andrewjl

CodeGeneration/Sources/SyntaxSupport/DeclNodes.swift

@@ -1813,6 +1813,18 @@ public let DECL_NODES: [Node] = [
   Node(
     name: "StructDecl",
     nameForDiagnostics: "struct",
+    description: """
+          A struct declaration like the following.
+
+          ```swift
+          struct SomeStruct {
+              let someMember: String
+              var anotherMember: Int
+          }
+          ```
+
+          A struct can optionally declare no members.
+      """,
     kind: "Decl",
     traits: [
       "DeclGroup",
@@ -1824,43 +1836,51 @@ public let DECL_NODES: [Node] = [
         name: "Attributes",
         kind: .collection(kind: "AttributeList", collectionElementName: "Attribute"),
         nameForDiagnostics: "attributes",
+        description: "Attributes that are attached to the struct.",
         isOptional: true
       ),
       Child(
         name: "Modifiers",
         kind: .collection(kind: "ModifierList", collectionElementName: "Modifier"),
         nameForDiagnostics: "modifiers",
+        description: "Modifiers that are attached to the struct.",
         isOptional: true
       ),
       Child(
         name: "StructKeyword",
-        kind: .token(choices: [.keyword(text: "struct")])
+        kind: .token(choices: [.keyword(text: "struct")]),
+        description: "The struct keyword."
       ),
       Child(
         name: "Identifier",
-        kind: .token(choices: [.token(tokenKind: "IdentifierToken")])
+        kind: .token(choices: [.token(tokenKind: "IdentifierToken")]),
+        description: "The struct identifier."
       ),
       Child(
         name: "GenericParameterClause",
         kind: .node(kind: "GenericParameterClause"),
         nameForDiagnostics: "generic parameter clause",
+        description: "The generic parameters of the struct.",
         isOptional: true
       ),
       Child(
         name: "InheritanceClause",
         kind: .node(kind: "TypeInheritanceClause"),
         nameForDiagnostics: "type inheritance clause",
+        description: "The inheritance clause of the struct type. This clause can contain only one or more protocols.",
         isOptional: true
       ),
       Child(
         name: "GenericWhereClause",
         kind: .node(kind: "GenericWhereClause"),
         nameForDiagnostics: "generic where clause",
+        description: "The generic where clause of the struct",
         isOptional: true
       ),
       Child(
         name: "MemberBlock",
-        kind: .node(kind: "MemberDeclBlock")
+        kind: .node(kind: "MemberDeclBlock"),
+        description: "The members of the struct. Struct extensions may declare additional members so the contents of this block should not be assumed to be the complete member list for this struct."
       ),
     ]
   ),