System.Buffers docs

Author: ericstj

xml/System.Buffers/ArrayBufferWriter`1.xml

@@ -227,6 +227,7 @@ You must request a new buffer after calling `Advance` to continue writing more d
 You must clear the <xref:System.Buffers.ArrayBufferWriter`1> before trying to reuse it.
           ]]></format>
         </remarks>
+        <seealso cref="M:System.Buffers.ArrayBufferWriter`1.ResetWrittenCount" />
       </Docs>
     </Member>
     <Member MemberName="FreeCapacity">
@@ -385,8 +386,9 @@ This method never returns <xref:System.Span%601.Empty?displayProperty=nameWithTy
       </ReturnValue>
       <Parameters />
       <Docs>
-        <summary>To be added.</summary>
-        <remarks>To be added.</remarks>
+        <summary>Resets the data written to the underlying buffer without zeroing its content.</summary>
+        <remarks>&lt;para&gt;&lt;para&gt; You must reset or clear the &lt;see cref="T:System.Buffers.ArrayBufferWriter`1" /&gt; before trying to re-use it.&lt;/para&gt;&lt;para&gt;&lt;/para&gt;&lt;para&gt; If you reset the writer using the &lt;see cref="M:System.Buffers.ArrayBufferWriter`1.ResetWrittenCount" /&gt; method, the underlying buffer will not be cleared.&lt;/para&gt;&lt;para&gt;&lt;/para&gt;</remarks>
+        <seealso cref="M:System.Buffers.ArrayBufferWriter`1.Clear" />
       </Docs>
     </Member>
     <Member MemberName="WrittenCount">