Add missing doc for ICustomTypeDescriptor

Author: steveharter

xml/System.ComponentModel/ICustomTypeDescriptor.xml

@@ -332,9 +332,16 @@
       </ReturnValue>
       <Parameters />
       <Docs>
-        <summary>Gets a type converter for this object that may be registered.</summary>
-        <returns>To be added.</returns>
-        <remarks>To be added.</remarks>
+        <summary>Returns a type converter for this instance of a component that may be registered.</summary>
+        <returns>A <see cref="T:System.ComponentModel.TypeConverter" /> that is the converter for this object, or <see langword="null" /> if there is no <see cref="T:System.ComponentModel.TypeConverter" /> for this object.</returns>
+        <remarks>
+          <format type="text/markdown"><![CDATA[  
+  
+## Remarks  
+ If `null` is returned, use the default <xref:System.ComponentModel.TypeConverter>.  
+  
+ ]]></format>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="GetDefaultEvent">
@@ -678,9 +685,18 @@
       </ReturnValue>
       <Parameters />
       <Docs>
-        <summary>Gets the events for this instance of a component that may be registered.</summary>
-        <returns>To be added.</returns>
-        <remarks>To be added.</remarks>
+        <summary>Returns the events for this instance of a component that may be registered.</summary>
+        <returns>An <see cref="T:System.ComponentModel.EventDescriptorCollection" /> that represents the events for this component instance.</returns>
+        <remarks>
+          <format type="text/markdown"><![CDATA[  
+  
+## Remarks  
+ The events for this instance can differ from the set of events that the class provides. For example, if the component is site-based, the site can add or remove additional events.  
+  
+ Implementors can return <xref:System.ComponentModel.EventDescriptorCollection.Empty?displayProperty=nameWithType> if no properties are specified. This method should never return `null`.  
+  
+ ]]></format>
+        </remarks>
       </Docs>
     </Member>
     <MemberGroup MemberName="GetProperties">
@@ -856,9 +872,18 @@
       </ReturnValue>
       <Parameters />
       <Docs>
-        <summary>Gets the properties for this instance of a component that may be registered.</summary>
-        <returns>To be added.</returns>
-        <remarks>To be added.</remarks>
+        <summary>Returns the properties for this instance of a component that may be registered.</summary>
+        <returns>A <see cref="T:System.ComponentModel.PropertyDescriptorCollection" /> that represents the properties for this component instance.</returns>
+        <remarks>
+          <format type="text/markdown"><![CDATA[  
+  
+## Remarks  
+ The properties for this instance can differ from the set of properties that the class provides. For example, if the component is sited, the site can add or remove additional properties.  
+  
+ Implementers can return <xref:System.ComponentModel.PropertyDescriptorCollection.Empty?displayProperty=nameWithType> if no properties are specified. This method should never return `null`.  
+  
+ ]]></format>
+        </remarks>
       </Docs>
     </Member>
     <Member MemberName="GetPropertyOwner">