extend conversion process documentation

aptos-move/framework/aptos-framework/sources/delegation_pool.move

@@ -899,6 +899,8 @@ module aptos_framework::delegation_pool {
     /// Initialize a delegation pool from an existing owned staking contract.
     /// The newly created delegation pool will preserve the operator and commission fee. The staker becomes the pool
     /// owner and has the same delegated voter set.
+    /// The conversion fails if there is any pending-active stake on the staking contract or if the staker already owns
+    /// a delegation pool.
     public entry fun initialize_delegation_pool_from_staking_contract(
         staker: &signer,
         operator: address,

aptos-move/framework/aptos-framework/sources/staking_contract.move

@@ -784,6 +784,8 @@ module aptos_framework::staking_contract {
 
         // withdraw entire inactive stake and unlock commission produced so far
         distribute_internal(staker_address, operator, &mut staking_contract, &mut store.distribute_events);
+        // pending-inactive commission will be converted into pending-inactive shares owned by the operator
+        // within the newly created delegation pool
         request_commission_internal(
             operator,
             &mut staking_contract,