Port System.Net source comments to Docs (#2491)

* Port System.Net source comments to Docs

* Apply suggestions from code review

Suggestions by rpetrusha

Co-Authored-By: Ron Petrusha <[email protected]>

Author: carlossanlop

xml/System.Net.Security/CipherSuitesPolicy.xml

@@ -14,7 +14,7 @@
   </Base>
   <Interfaces />
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Specifies allowed cipher suites.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>

xml/System.Net.Security/SslClientAuthenticationOptions.xml

@@ -137,7 +137,7 @@
         <ReturnType>System.Net.Security.CipherSuitesPolicy</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Specifies the cipher suites allowed for TLS. When set to <see langword="null" />, the operating system default is used. Use extreme caution when changing this setting.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -293,4 +293,4 @@
       </Docs>
     </Member>
   </Members>
-</Type>
+</Type>

xml/System.Net.Security/SslServerAuthenticationOptions.xml

@@ -137,7 +137,7 @@
         <ReturnType>System.Net.Security.CipherSuitesPolicy</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Specifies the cipher suites allowed for TLS. When set to <see langword="null" />, the operating system default is used. Use extreme caution when changing this setting.</summary>
         <value>To be added.</value>
         <remarks>To be added.</remarks>
       </Docs>
@@ -293,4 +293,4 @@
       </Docs>
     </Member>
   </Members>
-</Type>
+</Type>

xml/System.Net.Sockets/UnixDomainSocketEndPoint.xml

@@ -18,7 +18,7 @@
   </Base>
   <Interfaces />
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Represents a Unix Domain Socket endpoint as a path.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>

xml/System.Net.WebSockets/ValueWebSocketReceiveResult.xml

@@ -23,7 +23,7 @@
     </Attribute>
   </Attributes>
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Represents the result of performing a single <see cref="M:System.Net.WebSockets.WebSocket.ReceiveAsync(System.Memory{System.Byte},System.Threading.CancellationToken)" /> operation on a <see cref="T:System.Net.WebSockets.WebSocket" />.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>