Move docs from book/ to docs/ (#8469) (#8471)

automerge

docs/art/passive-staking-callflow.msc

@@ -0,0 +1,30 @@
+msc {
+  hscale="2.2";
+   VoteSigner,
+   Validator,
+   Cluster,
+   StakerX,
+   StakerY;
+
+   |||;
+  Validator box Validator [label="boot.."];
+
+  VoteSigner <:> Validator [label="register\n\n(optional)"];
+  Validator => Cluster [label="VoteState::Initialize(VoteSigner)"];
+  StakerX => Cluster [label="StakeState::Delegate(Validator)"];
+  StakerY => Cluster [label="StakeState::Delegate(Validator)"];
+
+     |||;
+  Validator box Cluster [label="\nvalidate\n"];
+  Validator => VoteSigner [label="sign(vote)"];
+  VoteSigner >> Validator [label="signed vote"];
+
+  Validator => Cluster [label="gossip(vote)"];
+  ...;
+  ... ;
+  Validator abox Validator [label="\nmax\nlockout\n"];
+       |||;
+  Cluster box Cluster [label="credits redeemed (at epoch)"];
+
+
+}