Reorder sidebar (#292)

* Update SUMMARY.md

* Update and rename available-services.md to supported-networks.md

SUMMARY.md

@@ -62,13 +62,13 @@
 
 ## Safe{Core} API
 
-* [Available Services](safe-core-api/available-services.md)
-
 * [Service Architecture](safe-core-api/service-architecture.md)
   * [Safe Transaction Service](safe-core-api/safe-transaction-service.md)
 
 * [RPC Requirements](safe-core-api/rpc-requirements.md)
 
+* [Supported Networks](safe-core-api/supported-networks.md)
+
 ## Safe Apps SDK
 
 * [Overview](safe-apps/README.md)
@@ -80,5 +80,5 @@
 ## Miscellaneous
 
 * [Bug Bounty](miscellaneous/bug-bounty-program.md)
-* [Past paid bounties](miscellaneous/past-paid-bounties.md)
+  * [Past paid bounties](miscellaneous/past-paid-bounties.md)
 * [Contact us](miscellaneous/contact-us.md)

safe-core-api/available-services.md → safe-core-api/supported-networks.md

@@ -1,8 +1,8 @@
 ---
-description: This pages provides an overview of the available services
+description: This page provides an overview of the available services
 ---
 
-# Available Services
+# Supported Networks
 
 ## Safe Transaction Service