add argentx connector docs

docs/connectors/argentx.md

@@ -0,0 +1,46 @@
+# `web3-react` Documentation - ArgentX
+
+- [Install](#install)
+- [Arguments](#arguments)
+- [Example](#example)
+- [Errors](#errors)
+  - [NoStarknetProviderError](#nostarknetprovidererror)
+    - [Example](#example-1)
+  - [UserRejectedRequestError](#userrejectedrequesterror)
+    - [Example](#example-2)
+
+## Install
+
+`yarn add @web3-starknet-react/argentx-connector`
+
+## Arguments
+
+```typescript
+supportedChainIds?: number[]
+```
+
+**NOTE**: Currently only Goerli (chainId: 5) is supported. As soon as ArgentX supports mainnet (chainId: 1), I will add support for that.
+
+## Example
+
+```javascript
+import { ArgentXConnector } from '@web3-starknet-react/argentx-connector'
+
+const argentx = new ArgentXConnector({ supportedChainIds: [5] })
+```
+
+## Errors
+
+### NoEthereumProviderError
+
+#### Example
+
+```javascript
+import { NoStarknetProviderError } from '@web3-starknet-react/argentx-connector'
+
+function Component() {
+  const { error } = useStarknetReact()
+  const isNoStarknetProviderError = error instanceof NoStarknetProviderError
+  // ...
+}
+```