Update contracts.md

Author: raullenchai

deployment/contracts.md

@@ -5,3 +5,17 @@
 `io1lfl4ppn2c3wcft04f0rk0jy9lyn4pcjcm7638u`
 
 This is the smart contract that managed how much a delegate will share the rewards with his/her voters, which can be set via member.iotex.io and will be used by hermes when distributing rewards.
+
+
+
+## VITA Bidding Pool
+`io16alj8sw7pt0d5wv22gdyphuyz9vas5dk8czk88`
+
+This is the smart contract that managed bidding of VITA token.
+
+## Native Staking Version 1 (nsv1) Contracts
+
+`io1xpq62aw85uqzrccg9y5hnryv8ld2nkpycc3gza`
+`io1zn9mn4v63jg3047ylqx9nqaqz0ev659777q3xc`
+
+These two smart contracts were used for staking and voting before mainnet GA which are now deprecated. **All IOTX here are locked/burned**.