Remove outdated child validation language

These paragraphs are no longer needed now that the keywords
are clearly designated as Applicators.  Both the general
applicator section and the introduction to this vocabulary
cover the behavior clearly.

Note that the remaining phrasing is still too validation-centric.
This will be addressed in the future.

jsonschema-core.xml

@@ -1230,10 +1230,6 @@
                             The value of "items" MUST be either a valid JSON Schema or an array of valid
                             JSON Schemas.
                         </t>
-                        <t>
-                            This keyword determines how child instances validate for arrays,
-                            and does not directly validate the immediate instance itself.
-                        </t>
                         <t>
                             If "items" is a schema, validation succeeds if all elements
                             in the array successfully validate against that schema.
@@ -1252,10 +1248,6 @@
                         <t>
                             The value of "additionalItems" MUST be a valid JSON Schema.
                         </t>
-                        <t>
-                            This keyword determines how child instances validate for arrays,
-                            and does not directly validate the immediate instance itself.
-                        </t>
                         <t>
                             If "items" is an array of schemas, validation succeeds
                             if every instance element at a position greater than the size
@@ -1288,10 +1280,6 @@
                             The value of "properties" MUST be an object.
                             Each value of this object MUST be a valid JSON Schema.
                         </t>
-                        <t>
-                            This keyword determines how child instances validate for objects,
-                            and does not directly validate the immediate instance itself.
-                        </t>
                         <t>
                             Validation succeeds if, for each name that appears in both
                             the instance and as a name within this keyword's value, the child
@@ -1310,12 +1298,6 @@
                             ECMA 262 regular expression dialect. Each property value of this object
                             MUST be a valid JSON Schema.
                         </t>
-                        <t>
-                            This keyword determines how child instances validate for objects,
-                            and does not directly validate the immediate instance itself.
-                            Validation of the primitive instance type against this keyword
-                            always succeeds.
-                        </t>
                         <t>
                             Validation succeeds if, for each instance name that matches any
                             regular expressions that appear as a property name in this keyword's value,
@@ -1331,10 +1313,6 @@
                         <t>
                             The value of "additionalProperties" MUST be a valid JSON Schema.
                         </t>
-                        <t>
-                            This keyword determines how child instances validate for objects,
-                            and does not directly validate the immediate instance itself.
-                        </t>
                         <t>
                             Validation with "additionalProperties" applies only to the child
                             values of instance names that do not match any names in "properties",