Revert "Update ConfigurationRoot.xml (correctly now?)"

This reverts commit 7f94e3f.

Author: Grzegorz Suwaj

xml/Microsoft.Extensions.Configuration/ConfigurationRoot.xml

@@ -93,8 +93,6 @@
         <param name="providers">The <see cref="T:Microsoft.Extensions.Configuration.IConfigurationProvider" />s for this configuration.</param>
         <summary>Initializes a Configuration root with a list of providers.</summary>
         <remarks>To be added.</remarks>
-        <exception cref="T:System.ArgumentNullException">
-          <paramref name="providers" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="Dispose">
@@ -236,7 +234,7 @@
         <param name="key">The key of the configuration section.</param>
         <summary>Gets a configuration sub-section with the specified key.</summary>
         <returns>The <see cref="T:Microsoft.Extensions.Configuration.IConfigurationSection" />.</returns>
-        <remarks>This method will never return <see langword="null" />. If no matching sub-section is found with the specified key,
+        <remarks>This method will never return <see langword="null" />. If no matching sub-section is found with the specified key,
                 an empty <see cref="T:Microsoft.Extensions.Configuration.IConfigurationSection" /> will be returned.</remarks>
       </Docs>
     </Member>