docs: add faq/merkle verification for post fustion

docs/bc-fusion/post-fusion/faq.md

@@ -0,0 +1,68 @@
+# FAQ
+
+## 1. What will happen during and after the final sunset hardfork?
+
+Before executing Final Sunset, users still have the opportunity to transfer funds across chains. However, after Final
+Sunset, cross-chain communication between the Beacon Chain and BSC will be completely stopped.
+
+After Sunset Fork (i.e., post fusion), the validators in the Beacon Chain community will gradually shut down, and the entire chain will no
+longer accept new transactions or propose new blocks.
+
+Some of the funds will be permanently locked:
+
+* On the Beacon Chain, the BEP2/BEP8 tokens that are not mirrored or bound to BSC.
+* The BEP153 staking reward that is less than 0.1BNB or staked value which is less than 0.01BNB will be locked forever.
+
+All these funds are not recoverable after the Final Sunset Fork.
+
+After BC shutdown, the core dev team will dump the ledger of Beacon Chain and generate a merkle tree.
+A governance proposal will be submitted to set the merkel root and approver account of the token migration contract.
+A dapp (token recovery dApp) will be provided for token migration from Beacon Chain to BSC.
+All the blockchain data of Beacon Chain will be uploaded to Greenfield, Filecoin and Arweave for archive.
+
+## 2.What users should do to manage their BEP2/BEP8 assets before and after the fusion?
+
+Before the final sunset hardfork:
+
+* Users should cross-chain transfer the BNB and bound BEP2/BEP8 to the BSC network.
+
+After the final sunset hadfork (i.e., post fusion):
+
+* Users should wait for the release of token recovery dApp, and use the token recovery dApp to get the assets back on
+  the BSC network.
+
+Important: to use the token recovery dApp, the private key/mnemonic for your BC account will be used to prove that you
+are the owner of the assets. Please take care of your key/mnemonic.
+
+## 3. How do users access the balance snapshot post fusion?
+
+* Several BC nodes (not validators) will be kept for users to query the blockchain data, including the user balances.
+    - Testnet RPC Node: https://data-seed-pre-0-s1.bnbchain.org/
+    - Mainnet RPC Node: To be updated.
+* An API endpoint will be kept for querying the snapshot balance.
+    - Testnet API Endpoint: https://testnet-dex.binance.org/api/v1/account/{tbnb_address}
+    - Mainnet API Endpoint: To be updated.
+* The snapshot file can be downloaded from Greenfield/IPFS/Arweave. The users can download the snapshot file and set up
+  a local BC node for retrieving any data on the blockchain.
+    - Testnet snpashot file: To be updated.    
+    - Mainnet snpashot file: To be updated.
+
+## 4. Can I still acccess the BC releated services or products after the fusion?
+
+Most of the BC related services and products will be shut down after the final sunset hardfork, inluding and not limited to:
+
+* Staking service (including UI/API) 
+    - Testnet staking service: https://testnet-staking.bnbchain.org/en/staking
+    - Mainnet staking service: https://www.bnbchain.org/en/staking
+* Block service (including API)
+    - Testnet block service: https://testnet-api.binance.org/bc
+    - Mainnet block service: https://api.binance.org/bc/
+
+In case you need any data from the Beacon Chain, you can still access the data from the snapshot file.
+
+The Beacon Chain Explorer will keep running for users to query the blockchain data, however we will consider to shutdown 
+the explorer for BC testnet if there is no query traffic for a long time.
+
+* Explorer service (including UI)
+    - Testnet explorer service: https://testnet-explorer.bnbchain.org/
+    - Mainnet explorer service: https://explorer.binance.org/

docs/bc-fusion/post-fusion/merkle-tree-verify.md

@@ -0,0 +1,14 @@
+# Verify Merkle Tree Proofs
+
+The [BEP299](https://github.com/bnb-chain/BEPs/blob/master/BEPs/BEP-299.md) describes how to recover 
+the bound BEP2/BEP8 on the BSC afer the fusion. One of the most important steps is to generate and verify 
+the Beacon Chain merkle tree proofs. If a wrong merkle tree root is generated, the bound BEP2/BEP8 
+cannot be recovered and there will a huge financial loss.
+
+Therefore, the communities are encouraged to use the following tools to verify the proofs and report any issues.
+
+To do the verification, please follow the detailed steps in the following links:
+
+* https://github.com/bnb-chain/node-dump/blob/master/Readme.md
+
+* https://github.com/bnb-chain/node-dump/blob/master/docs/verification.md

mkdocs.yml

@@ -76,6 +76,9 @@ nav:
   - BNB Chain Fusion:
     - BNB Chain Fusion: ./bc-fusion/index.md
     - Overview: ./bc-fusion/overview.md
+    - Post Fustion:
+      - Merkle Proof Verification: ./bc-fusion/post-fusion/merkle-tree-verify.md
+      - FAQ: ./bc-fusion/post-fusion/faq.md
     - For Users:
       - Manage Your Assets: ./bc-fusion/users/assets.md
       - Manage Your Atomic Swaps: ./bc-fusion/users/swaps.md