Merge pull request elizaOS#1095 from nicky-ru/docs-plugin-evm-readme

docs: add README.md to plugin-evm

Author: shakkernerd

packages/plugin-evm/README.md

@@ -0,0 +1,93 @@
+# `@ai16z/plugin-evm`
+
+This plugin provides actions and providers for interacting with EVM-compatible chains.
+
+---
+
+## Configuration
+
+### Default Setup
+
+By default, **Ethereum mainnet** is enabled. To use it, simply add your private key to the `.env` file:
+
+```env
+EVM_PRIVATE_KEY=your-private-key-here
+```
+
+### Adding Support for Other Chains
+
+To enable support for additional chains, add them to the character config like this:
+
+```json
+"settings": {
+    "chains": {
+        "evm": [
+            "base", "arbitrum", "iotex"
+        ]
+    }
+}
+```
+
+Note: The chain names must match those in the viem/chains.
+
+### Custom RPC URLs
+
+By default, the RPC URL is inferred from the `viem/chains` config. To use a custom RPC URL for a specific chain, add the following to your `.env` file:
+
+```env
+ETHEREUM_PROVIDER_<CHAIN_NAME>=https://your-custom-rpc-url
+```
+
+**Example usage:**
+
+```env
+ETHEREUM_PROVIDER_IOTEX=https://iotex-network.rpc.thirdweb.com
+```
+
+#### Custom RPC for Ethereum Mainnet
+
+To set a custom RPC URL for Ethereum mainnet, use:
+
+```env
+EVM_PROVIDER_URL=https://your-custom-mainnet-rpc-url
+```
+
+## Provider
+
+The **Wallet Provider** initializes with the **first chain in the list** as the default (or Ethereum mainnet if none are added). It:
+
+- Provides the **context** of the currently connected address and its balance.
+- Creates **Public** and **Wallet clients** to interact with the supported chains.
+- Allows adding chains dynamically at runtime.
+
+---
+
+## Actions
+
+### Transfer
+
+Transfer tokens from one address to another on any EVM-compatible chain. Just specify the:
+
+- **Amount**
+- **Chain**
+- **Recipient Address**
+
+**Example usage:**
+
+```bash
+Transfer 1 ETH to 0xRecipient on arbitrum.
+```
+
+---
+
+## Contribution
+
+The plugin contains tests. Whether you're using **TDD** or not, please make sure to run the tests before submitting a PR.
+
+### Running Tests
+
+Navigate to the `plugin-evm` directory and run:
+
+```bash
+pnpm test
+```