Refs #547 -- Add content about using Pyth oracle to obtain random numbers

docs/espace/tutorials/oracle/Pyth/_category_.json

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+{
+    "label": "Pyth",
+    "position": 1,
+    "link": {
+      "type": "generated-index",
+      "description": "Tutorial on how to use a Oracle on Conflux eSpace"
+    }
+  }
+

docs/espace/tutorials/oracle/Pyth/priceFeed.md

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+---
+displayed_sidebar: eSpaceSidebar
+---
+TODO

docs/espace/tutorials/oracle/Pyth/randomNumbers.md

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+---
+displayed_sidebar: eSpaceSidebar
+---
+# Retrieve Random Numbers
+
+This tutorial will guide you through building a project on Conflux eSpace using Hardhat and retrieving random numbers through the Pyth Oracle.
+
+## Prerequisites
+
+Before starting, ensure you have the following software installed:
+
+1. Node.js and npm
+2. Hardhat
+3. ConfluxPortal wallet extension
+
+## Step 1: Create a Hardhat Project
+
+First, we need to create a new Hardhat project.
+
+```bash
+mkdir conflux-pyth-random
+cd conflux-pyth-random
+npm init -y
+npx hardhat init
+```
+
+Follow the prompts and choose the default options to create a basic JavaScript project and install the required dependencies.
+
+![Create Project](../../img/pyth-random-create.png)
+
+## Step 2: Install Necessary Dependencies
+
+Install the Pyth client library and Conflux-related dependencies.
+
+```bash
+npm install @pythnetwork/pyth-sdk-solidity @pythnetwork/entropy-sdk-solidity dotenv
+```
+
+## Step 3: Configure Hardhat
+
+Configure the Conflux eSpace network in `hardhat.config.js`.
+
+```javascript
+require("@nomicfoundation/hardhat-toolbox");
+require("dotenv").config();
+
+module.exports = {
+  solidity: "0.8.4",
+  networks: {
+    conflux: {
+      url: "https://evmtestnet.confluxrpc.com",
+      accounts: [process.env.PRIVATE_KEY],
+    },
+  },
+};
+```
+
+## Step 4: Write the Smart Contract
+
+Create a file named `RandomNumber.sol` in the `contracts` directory and add the following code:
+
+```solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.4;
+
+import "@pythnetwork/entropy-sdk-solidity/IEntropyConsumer.sol";
+import "@pythnetwork/entropy-sdk-solidity/IEntropy.sol";
+
+contract RandomNumber is IEntropyConsumer {
+    IEntropy private entropy;
+
+    constructor(address _entropy) {
+        entropy = IEntropy(_entropy);
+    }
+
+    // This method is required by the IEntropyConsumer interface.
+    // It returns the address of the entropy contract which will call the callback.
+    function getEntropy() internal view override returns (address) {
+        return address(entropy);
+    }
+
+    // It is called by the entropy contract when a random number is generated.
+    function entropyCallback(
+        uint64 sequenceNumber,
+        // If your app uses multiple providers, you can use this argument to
+        // distinguish which one is calling the app back.
+        address provider,
+        bytes32 randomNumber
+    ) internal override {
+        // Implement your callback logic here.
+        uint256 randomNum = uint256(randomNumber);
+
+        // Use the random number
+    }
+
+    function getRandomNumber() public payable {
+        address provider = entropy.getDefaultProvider();
+        uint fee = entropy.getFee(provider);
+        // This method returns a sequence number and emits a RequestedWithCallback event.
+        uint64 sequenceNumber = entropy.requestWithCallback{value: fee}(
+            provider,
+            keccak256(abi.encodePacked(block.timestamp))
+        );
+        // You can store this sequence number to identify the request in next step.
+    }
+}
+
+```
+
+When the final random number is ready to use, the entropyCallback function will be called by the Entropy contract. This will happen in a separate transaction submitted by the requested provider. The entropyCallback function should be implemented in the same contract that is requesting the random number.
+
+## Step 5: Deploy the Smart Contract
+
+Create a file named `deploy.js` in the `scripts` directory and add the following code:
+
+```javascript
+async function main() {
+  const [deployer] = await ethers.getSigners();
+
+  console.log("Deploying contracts with the account:", deployer.address);
+
+  // eSpace Testnet
+  const entropyAddress = "0xdF21D137Aadc95588205586636710ca2890538d5"; // Replace with the actual Entropy contract address
+
+  const RandomNumber = await ethers.getContractFactory("RandomNumber");
+  const randomNumber = await RandomNumber.deploy(entropyAddress);
+
+  await randomNumber.waitForDeployment(); // Ensure the contract is deployed
+
+  console.log("RandomNumber contract deployed to:", randomNumber.target);
+}
+
+main()
+  .then(() => process.exit(0))
+  .catch((error) => {
+    console.error(error);
+    process.exit(1);
+  });
+
+```
+
+You can consult the current [Entropy contract addresses](https://docs.pyth.network/entropy/contract-addresses) to find the address on Conflux eSpace, which is `0xdF21D137Aadc95588205586636710ca2890538d5`.
+
+## Step 6: Run the Deployment Script
+
+Deploy the contract using the following command:
+
+```bash
+npx hardhat run scripts/deploy.js --network conflux
+```
+
+## Step 7: Interact with the Contract
+
+After deployment, you can interact with the contract using the Hardhat console or a script. For example, create a file named `interact.js` in the `scripts` directory:
+
+```javascript
+async function main() {
+  const [deployer] = await ethers.getSigners();
+
+  const RandomNumber = await ethers.getContractFactory("RandomNumber");
+  const randomNumber = RandomNumber.attach(
+    "0x9807945B3f004B7b9812FDd4E131693176749e12"
+  ); // Replace with the actual contract address
+
+  // Request a random number
+  const tx = await randomNumber.getRandomNumber({
+    value: ethers.parseEther("0.01"),
+  }); // Adjust the value based on the required fee
+  await tx.wait();
+}
+
+main()
+  .then(() => process.exit(0))
+  .catch((error) => {
+    console.error(error);
+    process.exit(1);
+  });
+
+```
+
+Run the script using the following command:
+
+```bash
+npx hardhat run scripts/interact.js --network conflux
+```
+
+## Summary
+
+Through this tutorial, you have learned how to build a project on Conflux eSpace using Hardhat and retrieve random numbers through the Pyth Oracle. For more information, refer to the [Pyth Oracle official documentation](https://docs.pyth.network/).

docs/espace/tutorials/oracle/_category_.json

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+{
+    "label": "How to use Oracle",
+    "position": 1,
+    "link": {
+      "type": "generated-index",
+      "description": "Tutorial on how to use a Oracle on Conflux eSpace"
+    }
+  }
+