docs: add system contracts for bc fusion (#282)

docs/bcfusion/developers/system-contracts.md

@@ -0,0 +1,66 @@
+# Build-in System Contracts
+
+This section will provide a brief overview of the new build-in system contracts in the BNB Smart Chain.
+There contracts are are introduced in the [Feynman upgrade](https://github.com/bnb-chain/bsc/releases/tag/v1.3.10).
+
+For the sytem contracts which are already existed, please refer
+to [this document](https://docs.bnbchain.org/docs/learn/system-contract/).
+
+GitHub Implementation link: https://github.com/bnb-chain/bsc-genesis-contract
+
+| Contract Name | Contract Address | ABI File |
+|-------------------------------|--------------------------------------------|----------------------------------------------------------------------------------------------------------------|
+| Stake Hub Contract | 0x0000000000000000000000000000000000002002 | [stakehub](https://github.com/bnb-chain/bsc-genesis-contract/blob/master/abi/stakehub.abi) |
+| Stake Credit Contract | 0x0000000000000000000000000000000000002003 | [stakecredit](https://github.com/bnb-chain/bsc-genesis-contract/blob/master/abi/stakecredit.abi) |
+| Governor Contract | 0x0000000000000000000000000000000000002004 | [bscgovernor](https://github.com/bnb-chain/bsc-genesis-contract/blob/master/abi/bscgovernor.abi) |
+| Gov Token Contract | 0x0000000000000000000000000000000000002005 | [govtoken](https://github.com/bnb-chain/bsc-genesis-contract/blob/master/abi/govtoken.abi) |
+| Timelock Contract | 0x0000000000000000000000000000000000002006 | [bsctimelock](https://github.com/bnb-chain/bsc-genesis-contract/blob/master/abi/bsctimelock.abi) |
+| Token Recover Portal Contract | 0x0000000000000000000000000000000000003000 | [tokenrecoverportal](https://github.com/bnb-chain/bsc-genesis-contract/blob/master/abi/tokenrecoverportal.abi) |
+
+### Precompiled Contracts
+
+### Secp256k1 Signature Recover
+
+The precompiled contract is used to verify the signature of a message signed using the secp256k1 elliptic curve
+cryptography algorithm. It will also retrun the Tendermint address of the signer.
+
+### Verify Double Sign Evidence
+
+The precompiled contract is used to verify the submitted double sign evidence,
+which includes the two block headers signed by the same validator at different times.
+
+## Build-in System Contracts
+
+### Stake Hub Contract
+
+The Stake Hub contract is a contract that manages the staking process, including delegation, undelegation, redelegation,
+and claiming rewards.
+
+### Stake Credit Contract
+
+The Stake Credit contract is a template proxy contract. When a is created, a new stake credit contract is deployed,
+to manage staking credit and facilitate the exchange between credit and BNB.
+
+### Governor Contract
+
+The Governor contract is a contract that manages the BNB Smart Chain governance process.
+It allows users to propose and vote on changes to the protocol.
+
+### Gov Token Contract
+
+The Gov Token contract is a contract that manages the governance token, i.e., `govBNB`.
+
+### Timelock Contract
+
+The Timelock contract is a contract that allows executing a time lock on some specific operations (e.g., token
+recovery).
+After the timelock period, the locked tokens can be claimed or released.
+
+### Token Recover Portal Contract
+
+The Token Recover Portal contract is a contract that allows users to recover their BEP2/BEP8 tokens,
+which must have been bound to BEP20 tokens, after the shutdown of the cross-chaind transfer between
+BNB Smart Chain and BNB Beacon Chain. 
+
+
+

sidebars.js

@@ -334,6 +334,7 @@ const sidebars = {
  {type:'doc', id:'bcfusion/developers/staking', label:'New Staking'},
  {type:'doc', id:'bcfusion/developers/gov', label:'New Governance'},
  {type:'doc', id:'bcfusion/developers/crosschain-redelegation', label:'Cross Chain Redelegation'},
+ {type:'doc', id:'bcfusion/developers/system-contracts', label:'Build-in System Contracts'},
  ]
  },
  {