Move mermaid diagram of block production to docs directory.

docs/block_production/lifecycle.md

@@ -0,0 +1,27 @@
+The following diagram describes Leap block production, as implemented in `libraries/chain/controller.cpp`:
+
+```mermaid
+flowchart TD
+    pp[producer_plugin] --> D
+    A("`_replay()_`"):::fun --> B("`_replay_push_block()_`"):::fun
+    B --> E("`_maybe_switch_forks()_`"):::fun
+    C("`_init()_`"):::fun ---> E
+    C --> A
+    D("`_push_block()_`"):::fun ---> E
+    subgraph G["`**_apply_block()_**`"]
+       direction TB
+       start -- "stage = Ø" --> sb
+       sb("`_start_block()_`"):::fun -- stage = building_block --> et
+       et["execute transactions" ] -- stage = building_block --> fb("`_finalize_block()_`"):::fun
+       fb -- stage = assembled block --> cb["add transaction metadata and create completed block"]
+       cb -- stage = completed block --> commit("`_commit_block()_ where we [maybe] add to fork_db and mark valid`"):::fun
+
+    end
+    B ----> start
+    E --> G
+    D --> F("`_log_irreversible()_`"):::fun
+    commit -- stage =  Ø -->  F
+    F -- if in irreversible mode --> G
+
+    classDef fun fill:#f96
+```

libraries/chain/controller.cpp

@@ -43,35 +43,7 @@
 #include <shared_mutex>
 #include <utility>
 
-/* ----------- Mermaid diagram -----------------------------------
-
-flowchart TD
-    pp[producer_plugin] --> D
-    A("`_replay()_`"):::fun --> B("`_replay_push_block()_`"):::fun
-    B --> E("`_maybe_switch_forks()_`"):::fun
-    C("`_init()_`"):::fun ---> E
-    C --> A
-    D("`_push_block()_`"):::fun ---> E
-    subgraph G["`**_apply_block()_**`"]
-       direction TB
-       start -- "stage = &Oslash;" --> sb
-       sb("`_start_block()_`"):::fun -- stage = building_block --> et
-       et["execute transactions" ] -- stage = building_block --> fb("`_finalize_block()_`"):::fun
-       fb -- stage = assembled block --> cb["add transaction metadata and create completed block"]
-       cb -- stage = completed block --> commit("`_commit_block()_ where we [maybe] add to fork_db and mark valid`"):::fun
-
-    end
-    B ----> start
-    E --> G
-    D --> F("`_log_irreversible()_`"):::fun
-    commit -- stage =  &Oslash; -->  F
-    F -- if in irreversible mode --> G
-
-    classDef fun fill:#f96
-
------------------------------------------------------------------- */
-
-namespace eosio { namespace chain {
+namespace eosio::chain {
 
 using resource_limits::resource_limits_manager;
 
@@ -4587,4 +4559,4 @@ void controller_impl::on_activation<builtin_protocol_feature_t::instant_finality
 
 /// End of protocol feature activation handlers
 
-} } /// eosio::chain
+} /// eosio::chain