feat: add new API endpoints and examples for currency conversion and max buy/sell amount

- Added `getConvertCurrencyPair` and `getMaxBuySellAmount` endpoints to the documentation.
- Created example scripts for calling the new endpoints using the OKX API client.

Author: JJ-Cro

docs/endpointFunctionList.md

@@ -64,6 +64,7 @@ This table includes all endpoints from the official Exchange API docs and corres
 | [setSettleCurrency()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L528) | :closed_lock_with_key:  | POST | `/api/v5/account/set-settle-currency` |
 | [setFeeType()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L534) | :closed_lock_with_key:  | POST | `/api/v5/account/set-fee-type` |
 | [setLeverage()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L538) | :closed_lock_with_key:  | POST | `/api/v5/account/set-leverage` |
+| [getMaxBuySellAmount()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L543) | :closed_lock_with_key:  | GET | `/api/v5/account/max-size` |
 | [getMaxAvailableTradableAmount()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L556) | :closed_lock_with_key:  | GET | `/api/v5/account/max-avail-size` |
 | [changePositionMargin()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L566) | :closed_lock_with_key:  | POST | `/api/v5/account/position/margin-balance` |
 | [getLeverage()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L572) | :closed_lock_with_key:  | GET | `/api/v5/account/leverage-info` |
@@ -345,6 +346,7 @@ This table includes all endpoints from the official Exchange API docs and corres
 | [applyForMonthlyStatement()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L2569) | :closed_lock_with_key:  | POST | `/api/v5/asset/monthly-statement` |
 | [getMonthlyStatement()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L2573) | :closed_lock_with_key:  | GET | `/api/v5/asset/monthly-statement` |
 | [getConvertCurrencies()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L2577) | :closed_lock_with_key:  | GET | `/api/v5/asset/convert/currencies` |
+| [getConvertCurrencyPair()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L2581) | :closed_lock_with_key:  | GET | `/api/v5/asset/convert/currency-pair` |
 | [estimateConvertQuote()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L2590) | :closed_lock_with_key:  | POST | `/api/v5/asset/convert/estimate-quote` |
 | [convertTrade()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L2594) | :closed_lock_with_key:  | POST | `/api/v5/asset/convert/trade` |
 | [getConvertHistory()](https://github.com/tiagosiebler/okx-api/blob/master/src/rest-client.ts#L2598) | :closed_lock_with_key:  | GET | `/api/v5/asset/convert/history` |

examples/apidoc/RestClient/getConvertCurrencyPair.js

@@ -0,0 +1,23 @@
+import { RestClient } from 'okx-api';
+// or, if require is preferred:
+// const { RestClient } = require('okx-api');
+
+// This example shows how to call this OKX API endpoint with either node.js, javascript (js) or typescript (ts) with the npm module "okx-api" for OKX exchange
+// This OKX API SDK is available on npm via "npm install okx-api"
+// ENDPOINT: /api/v5/asset/convert/currency-pair
+// METHOD: GET
+// PUBLIC: NO
+
+const client = new RestClient({
+    apiKey: 'apiKeyHere',
+    apiSecret: 'apiSecretHere',
+    apiPass: 'apiPassHere',
+});
+
+client.getConvertCurrencyPair(params)
+  .then((response) => {
+    console.log(response);
+  })
+  .catch((error) => {
+    console.error(error);
+  });

examples/apidoc/RestClient/getMaxBuySellAmount.js

@@ -0,0 +1,23 @@
+import { RestClient } from 'okx-api';
+// or, if require is preferred:
+// const { RestClient } = require('okx-api');
+
+// This example shows how to call this OKX API endpoint with either node.js, javascript (js) or typescript (ts) with the npm module "okx-api" for OKX exchange
+// This OKX API SDK is available on npm via "npm install okx-api"
+// ENDPOINT: /api/v5/account/max-size
+// METHOD: GET
+// PUBLIC: NO
+
+const client = new RestClient({
+    apiKey: 'apiKeyHere',
+    apiSecret: 'apiSecretHere',
+    apiPass: 'apiPassHere',
+});
+
+client.getMaxBuySellAmount(params)
+  .then((response) => {
+    console.log(response);
+  })
+  .catch((error) => {
+    console.error(error);
+  });