Add missing docs in FieldTypeEncoder.CustomModifiers, ObsoletedOSPlatformAttribute (#8424)

* Add missing docs

* Apply suggestions from code review

Co-authored-by: Genevieve Warren <[email protected]>

Co-authored-by: Genevieve Warren <[email protected]>

Author: buyaa-n

xml/System.Reflection.Metadata.Ecma335/FieldTypeEncoder.xml

@@ -83,8 +83,8 @@
       </ReturnValue>
       <Parameters />
       <Docs>
-        <summary>Get <see cref="M:System.Reflection.Metadata.Ecma335.FieldTypeEncoder.CustomModifiers" /> to specify custom modifiers to the field signature.</summary>
-        <returns>To be added.</returns>
+        <summary>Gets the custom modifiers encoder to the field signature.</summary>
+        <returns>The encoder that specifies the custom modifiers to the field signature.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>

xml/System.Runtime.Versioning/ObsoletedOSPlatformAttribute.xml

@@ -40,8 +40,8 @@
         <Parameter Name="platformName" Type="System.String" />
       </Parameters>
       <Docs>
-        <param name="platformName">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="platformName">The obsoleted OS platform name, optionally including a version.</param>
+        <summary>Initializes a new instance of the <see cref="T:System.Runtime.Versioning.ObsoletedOSPlatformAttribute" /> class for the specified obsoleted OS platform.</summary>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -62,9 +62,9 @@
         <Parameter Name="message" Type="System.String" />
       </Parameters>
       <Docs>
-        <param name="platformName">To be added.</param>
-        <param name="message">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="platformName">The obsoleted OS platform name, optionally including a version.</param>
+        <param name="message">Additional information about the obsoletion, for example, a suggested alternative for the obsoleted API.</param>
+        <summary>Initializes a new instance of the <see cref="T:System.Runtime.Versioning.ObsoletedOSPlatformAttribute" /> attribute class for the specified obsoleted OS platform with an additional message.</summary>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -84,9 +84,9 @@
         <ReturnType>System.String</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
-        <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <summary>Gets the optional additional message provided for the attribute.</summary>
+        <value>A string that represents the message, or <see langword="null"/> if there is none.</value>
+        <remarks>Provides additional information about the obsoleted API, often to suggest a better alternative to use on the specified OS platform.</remarks>
       </Docs>
     </Member>
     <Member MemberName="Url">
@@ -105,8 +105,8 @@
         <ReturnType>System.String</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
-        <value>To be added.</value>
+        <summary>Gets or sets the URL for corresponding documentation.</summary>
+        <value>The string that represents a URL to corresponding documentation.</value>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>