Redfish.md: Add missing cable properties

CableType and LengthMeters were missing in Redfish.md. Added here:
9c929bea78857633f2b71b356abf4aa4b1ac56d2

Tested: None, document.

Change-Id: I7f705fcbf93bdd975d284700a63bc1fa8abe26d9
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/Redfish.md b/Redfish.md
index 29b6b87..deae38e 100644
--- a/Redfish.md
+++ b/Redfish.md
@@ -132,6 +132,21 @@
 - OemPrivileges
 - RoleId
 
+### /redfish/v1/Cables/
+
+#### CableCollection
+
+- Description
+- Members
+- Members@odata.count
+
+### /redfish/v1/Cables/{CableId}/
+
+#### Cable
+
+- CableType
+- LengthMeters
+
 ### /redfish/v1/CertificateService/
 
 #### CertificateService