doc: fix added: info for outgoingMessage.writable*

- `outgoingMessage.writableCorked` was added to Node.js v13.2.0 via
  62e15a7 and backported to Node.js v12.16.0 via db8144b.
- `outgoingMessage.writableEnded` was added to Node.js v12.9.0 via
  f9b61d2.
- `outgoingMessage.writableFinished` was added to Node.js v12.7.0 via
  06d0abe.
- `outgoingMessage.writableHighWaterMark`,
  `outgoingMessage.writableLength`, and
  `outgoingMessage.writableObjectMode` were added to Node.js v12.9.0 via
  16e0011.

PR-URL: #42737
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>
Reviewed-By: Mestery <mestery@protonmail.com>
Reviewed-By: Ricky Zhou <0x19951125@gmail.com>

Author: lpinca

doc/api/http.md

@@ -2729,7 +2729,9 @@ See [`writable.uncork()`][]
 ### `outgoingMessage.writableCorked`
 
 <!-- YAML
-added: v14.0.0
+added:
+  - v13.2.0
+  - v12.16.0
 -->
 
 * {number}
@@ -2740,7 +2742,7 @@ This `outgoingMessage.writableCorked` will return the time how many
 ### `outgoingMessage.writableEnded`
 
 <!-- YAML
-added: v13.0.0
+added: v12.9.0
 -->
 
 * {boolean}
@@ -2752,7 +2754,7 @@ purpose, use `message.writableFinished` instead.
 ### `outgoingMessage.writableFinished`
 
 <!-- YAML
-added: v13.0.0
+added: v12.7.0
 -->
 
 * {boolean}
@@ -2762,7 +2764,7 @@ Readonly. `true` if all data has been flushed to the underlying system.
 ### `outgoingMessage.writableHighWaterMark`
 
 <!-- YAML
-added: v13.0.0
+added: v12.9.0
 -->
 
 * {number}
@@ -2777,7 +2779,7 @@ buffered by the socket.
 ### `outgoingMessage.writableLength`
 
 <!-- YAML
-added: v13.0.0
+added: v12.9.0
 -->
 
 * {number}
@@ -2788,7 +2790,7 @@ bytes (or objects) in the buffer ready to send.
 ### `outgoingMessage.writableObjectMode`
 
 <!-- YAML
-added: v13.0.0
+added: v12.9.0
 -->
 
 * {boolean}