Fix migration order, comment on_runtime_upgrade

Author: gregzaitsev

pallets/subtensor/src/lib.rs

@@ -1203,14 +1203,21 @@ pub mod pallet {
                 "feabaafee293d3b76dae304e2f9d885f77d2b17adab9e17e921b321eccd61c77"
             ];
             weight = weight
+                // Initializes storage version (to 1)
                 .saturating_add(migration::migrate_to_v1_separate_emission::<T>())
+                // Storage version v1 -> v2
                 .saturating_add(migration::migrate_to_v2_fixed_total_stake::<T>())
+                // Doesn't check storage version. TODO: Remove after upgrade
                 .saturating_add(migration::migrate_create_root_network::<T>())
+                // Storage version v2 -> v3
                 .saturating_add(migration::migrate_transfer_ownership_to_foundation::<T>(
                     hex,
                 ))
-                .saturating_add(migration::migrate_delete_subnet_3::<T>())
+                // Storage version v3 -> v4
                 .saturating_add(migration::migrate_delete_subnet_21::<T>())
+                // Storage version v4 -> v5
+                .saturating_add(migration::migrate_delete_subnet_3::<T>())
+                // Doesn't check storage version. TODO: Remove after upgrade
                 .saturating_add(migration::migration5_total_issuance::<T>(false));
 
             weight