Merge pull request #400 from bloxbean/fabianbormann-update-docs

chore: update Koios backend example in README.md

backend-modules/koios/README.md

@@ -34,10 +34,10 @@ BackendService backendService = new KoiosBackendService(<Koios Instance Url>);
 
 **Example:**
 
-BackendService using Global Testnet Koios endpoint.
+BackendService using the Koios public preprod endpoint.
 
 ```
-BackendService backendService = new KoiosBackendService(Constant.KOIOS_TESTNET_URL);
+BackendService backendService = new KoiosBackendService(Constants.KOIOS_PREPROD_URL);
 ```
 
 **Note:** You can get other services from BackendService instance. For detailed api usage, check [cardano-client-lib](https://github.com/bloxbean/cardano-client-lib) project
@@ -53,4 +53,4 @@ $> ./gradlew -p ./backend-modules/koios/ clean build
 **Limitations**
 
 * Block Object Received By BlockService::getLatestBlock Endpoint will have null fields for Output Sum, Fees, and Num of Confirmations.  
-* Ordering is not supported for Account Addresses and Account Assets Endpoint.
+* Ordering is not supported for Account Addresses and Account Assets Endpoint.