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

automerge

core/src/repair_service.rs

@@ -317,7 +317,7 @@ impl RepairService {
         );
     }
 
-    // Update the gossiped structure used for the "Repairmen" repair protocol. See book
+    // Update the gossiped structure used for the "Repairmen" repair protocol. See docs
     // for details.
     fn update_epoch_slots(
         id: Pubkey,

core/tests/fork-selection.rs

@@ -1,6 +1,6 @@
 //! Fork Selection Simulation
 //!
-//! Description of the algorithm can be found in [book/src/fork-selection.md](book/src/fork-selection.md).
+//! Description of the algorithm can be found in [docs/src/fork-selection.md](docs/src/fork-selection.md).
 //!
 //! A test library function exists for configuring networks.
 //! ```