Fix link to basic guide

(cherry picked from commit 5ec7204948)

docs/modules/ROOT/nav.adoc

@@ -10,6 +10,7 @@
 
 .In Depth
 * xref:erc20-supply.adoc[ERC20 Supply]
+* xref:gsn-bouncers.adoc[GSN Bouncers]
 
 .FAQ
 * xref:api-stability.adoc[API Stability]

docs/modules/ROOT/pages/gsn-bouncers.adoc

@@ -6,7 +6,7 @@ First, we will explain the Bouncer concept, and then we will showcase how to use
 
 Finally, we will cover how to create your own custom Bouncer.
 
-If you're still learning about the basics of the Gas Station Network, you should head over to our xref:api:gsn.adoc[GSN Guide], which will help you get started from scratch.
+If you're still learning about the basics of the Gas Station Network, you should head over to our xref:gsn.adoc[GSN Guide], which will help you get started from scratch.
 
 [[gsn-bouncers]]
 == GSN Bouncers

docs/modules/ROOT/pages/gsn.adoc

@@ -89,4 +89,4 @@ These functions allow you to implement, for instance, a flow where you charge yo
 
 == Further reading
 
-Read our xref:gsn-advanced.adoc[guide on the payment strategies] (called _bouncers_) pre-built and shipped in OpenZeppelin Contracts, or check out xref:api:GSN.adoc[the API reference of the GSN base contracts].
+Read our xref:gsn-bouncers.adoc[guide on the payment strategies] (called _bouncers_) pre-built and shipped in OpenZeppelin Contracts, or check out xref:api:GSN.adoc[the API reference of the GSN base contracts].