Update thing-description schema for openhab/openhab-core#4079 (#460)

Signed-off-by: Kai Kreuzer <[email protected]>

.vuepress/public/schemas/thing-description-1.0.0.xsd

@@ -63,7 +63,7 @@
 
     <xs:complexType name="channelType">
         <xs:sequence>
-            <xs:element name="item-type" type="xs:string" minOccurs="0"/>
+            <xs:element name="item-type" type="thing-description:itemType" minOccurs="0"/>
             <xs:element name="kind" type="xs:string" minOccurs="0"/>
             <xs:element name="label" type="xs:string"/>
             <xs:element name="description" type="xs:string" minOccurs="0"/>
@@ -91,7 +91,6 @@
             <xs:element name="channels" type="thing-description:channels" minOccurs="0"/>
         </xs:sequence>
         <xs:attribute name="id" type="config-description:idRestrictionPattern" use="required"/>
-        <xs:attribute name="advanced" type="xs:boolean" default="false" use="optional"/>
     </xs:complexType>
 
     <xs:complexType name="supportedBridgeTypeRefs">
@@ -142,6 +141,14 @@
         <xs:attribute name="typeId" type="config-description:idRestrictionPattern" use="required"/>
     </xs:complexType>
 
+    <xs:complexType name="itemType">
+        <xs:simpleContent>
+            <xs:extension base="xs:string">
+                <xs:attribute name="unitHint" type="xs:string" use="optional" />
+            </xs:extension>
+        </xs:simpleContent>
+    </xs:complexType>
+
     <xs:complexType name="tags">
         <xs:sequence>
             <xs:element name="tag" type="xs:string" minOccurs="1" maxOccurs="unbounded"/>