Move compatibility changes of stdlib to that section

NEWS.md

@@ -120,23 +120,6 @@ Note: We're only listing outstanding class updates.
 
 ## Stdlib updates
 
-* Net::HTTP
-
-    * Removed the following deprecated constants:
-        `Net::HTTP::ProxyMod`
-        `Net::NetPrivate::HTTPRequest`
-        `Net::HTTPInformationCode`
-        `Net::HTTPSuccessCode`
-        `Net::HTTPRedirectionCode`
-        `Net::HTTPRetriableCode`
-        `Net::HTTPClientErrorCode`
-        `Net::HTTPFatalErrorCode`
-        `Net::HTTPServerErrorCode`
-        `Net::HTTPResponseReceiver`
-        `Net::HTTPResponceReceiver`
-
-      These constants were deprecated from 2012.
-
 * Tempfile
 
     * The keyword argument `anonymous: true` is implemented for Tempfile.create.
@@ -144,15 +127,6 @@ Note: We're only listing outstanding class updates.
       So applications don't need to remove the file.
       [[Feature #20497]]
 
-* Timeout
-
-    * Reject negative values for Timeout.timeout. [[Bug #20795]]
-
-* URI
-
-    * Switched default parser to RFC 3986 compliant from RFC 2396 compliant.
-      [[Bug #19266]]
-
 * win32/sspi.rb
 
     * This library is now extracted from the Ruby repository to [ruby/net-http-sspi].
@@ -303,6 +277,32 @@ details of the default gems or bundled gems.
 
 ## Stdlib compatibility issues
 
+* Net::HTTP
+
+    * Removed the following deprecated constants:
+        `Net::HTTP::ProxyMod`
+        `Net::NetPrivate::HTTPRequest`
+        `Net::HTTPInformationCode`
+        `Net::HTTPSuccessCode`
+        `Net::HTTPRedirectionCode`
+        `Net::HTTPRetriableCode`
+        `Net::HTTPClientErrorCode`
+        `Net::HTTPFatalErrorCode`
+        `Net::HTTPServerErrorCode`
+        `Net::HTTPResponseReceiver`
+        `Net::HTTPResponceReceiver`
+
+      These constants were deprecated from 2012.
+
+* Timeout
+
+    * Reject negative values for Timeout.timeout. [[Bug #20795]]
+
+* URI
+
+    * Switched default parser to RFC 3986 compliant from RFC 2396 compliant.
+      [[Bug #19266]]
+
 ## C API updates
 
 * `rb_newobj` and `rb_newobj_of` (and corresponding macros `RB_NEWOBJ`, `RB_NEWOBJ_OF`, `NEWOBJ`, `NEWOBJ_OF`) have been removed. [[Feature #20265]]