Update documentation

Author: jdhoek

doc/eight-byte-id-structure.md

@@ -5,14 +5,14 @@ The eight byte IDs generated by the `LocalUniqueIDGenerator` and
 `SynchronizedUniqueIDGenerator` classes conform to the following structure:
 
 ```
-TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTSSSSSS ...MGGGG GGGGCCCC
+TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTTTTTTT TTSSSSSS GGGMGGGG GGGGCCCC
 |                                              |      |  ||        |
 v                                              |      |  |\        |
                                                |      v  \ \       |
 Date of ID creation, measured in milliseconds  |          \ \      |
-ellapsed since 1970-01-01T00:00:00.000,        | Reserved  \ \     |
-represented in reverse byte-order (in SPREAD   | for future | |    |
-mode) to guarantee an even spread of IDs.      | use.       | |    |
+ellapsed since 1970-01-01T00:00:00.000,        | Generator \ \     |
+represented in reverse byte-order (in SPREAD   | ID, see    | |    |
+mode) to guarantee an even spread of IDs.      | below.     | |    |
                                                |            | |    |
                                                v            | |    |
                                                             | |    |
@@ -27,13 +27,13 @@ mode) to guarantee an even spread of IDs.      | use.       | |    |
                                                               v    |
                                                                    |
                     Generator ID, manually assigned, or acquired   |
-                    through negotiation via a ZooKeeper-quorum.    |
-                                                                   |
+                    through negotiation via Etcd. Limited to 2048  |
+                    per Cluster ID.                                |
                                                                    v
 
                                      Cluster ID. Always manually assigned
                                      or statically configured. Limited to
-                                     16 (actieve) clusters.
+                                     16 (active) clusters.
 ```
 
 This approach offers a few useful features: