types: restore KeyDigest assignment

refs #4645

Change-Id: I58a215ae8cf5a33cea422c6163fa745bdafa00c9
diff --git a/types.rst b/types.rst
index 4a44288..eb944ec 100644
--- a/types.rst
+++ b/types.rst
@@ -61,6 +61,8 @@
 +---------------------------------------------+------------------+-----------------+
 | KeyLocator                                  | 28               | 0x1c            |
 +---------------------------------------------+------------------+-----------------+
+| KeyDigest                                   | 29               | 0x1d            |
++---------------------------------------------+------------------+-----------------+
 |                     **Link Object**                                              |
 +---------------------------------------------+------------------+-----------------+
 | Delegation                                  | 31               | 0x1f            |
@@ -95,8 +97,6 @@
 +----------------+-----------------------------------------------------------+
 | 19             | Reserved, formerly `Any`                                  |
 +----------------+-----------------------------------------------------------+
-| 29             | Reserved, formerly `KeyDigest`                            |
-+----------------+-----------------------------------------------------------+
 | 32             | Reserved, formerly `SelectedDelegation`                   |
 +----------------+-----------------------------------------------------------+
 | 80-100         | Reserved for assignments related to local link data       |