Fixes broken links

docs/usage-guide/topics/SUMMARY.md

@@ -13,5 +13,5 @@
 - [Examining the Client Hello](./ch10-client-hello.md)
 - [Session Resumption](./ch11-resumption.md)
 - [Offloading Private Key Operations](./ch12-private-key-ops.md)
-- [Pre-shared Keys](./ch13-preshared_keys.md)
+- [Pre-shared Keys](./ch13-preshared-keys.md)
 - [Early Data](./ch14-early-data.md)

docs/usage-guide/topics/ch01-api.md

@@ -6,7 +6,7 @@ are intended to be stable (API and ABI) within major version numbers of s2n-tls
 and structures used in s2n-tls internally can not be considered stable and their parameters, names, and
 sizes may change.
 
-Read [Error Handling](./error_handling.md) for information on processing API return values safely.
+Read [Error Handling](./ch03-error-handling.md) for information on processing API return values safely.
 
 The [VERSIONING.rst](https://github.com/aws/s2n-tls/blob/main/VERSIONING.rst) document contains more details about s2n's approach to versions and API changes.
 

docs/usage-guide/topics/ch05-config.md

@@ -3,11 +3,11 @@
 `s2n_config` objects are used to change the default settings of a s2n-tls connection. Use `s2n_config_new()` to create a new config object. To associate a config with a connection call `s2n_connection_set_config()`. A config should not be altered once it is associated with a connection as this will produce undefined behavior. It is not necessary to create a config object per connection; one config object should be used for many connections. Call `s2n_config_free()` to free the object when no longer needed. _Only_ free the config object when all connections using it have been freed.
 
 Calling `s2n_config_new()` can have a performance cost during config creation due to loading
-default system certificates into the trust store (see [Configuring the Trust Store](./certificates.md#configuring-the-trust-store)).
+default system certificates into the trust store (see [Configuring the Trust Store](./ch09-certificates.md#configuring-the-trust-store)).
 For increased performance, use `s2n_config_new_minimal()` when system certificates are not needed
 for certificate validation.
 
-Most commonly, a `s2n_config` object is used to set the certificate key pair for authentication and change the default security policy. See the sections for [certificates](./certificates.md) and [security policies](./security_policies.md) for more information on those settings.
+Most commonly, a `s2n_config` object is used to set the certificate key pair for authentication and change the default security policy. See the sections for [certificates](./ch09-certificates.md) and [security policies](./ch06-security-policies.md) for more information on those settings.
 
 ## Overriding the Config
 

docs/usage-guide/topics/ch07-io.md

@@ -102,7 +102,7 @@ connections aborted while active.
 A single call to `s2n_send()` may involve multiple system calls to write the
 provided application data. s2n-tls breaks the application data into fixed-sized
 records before encryption, and calls write for each record.
-[See the record size documentation for how record size may impact performance](https://github.com/aws/s2n-tls/blob/main/docs/USAGE-GUIDE.md#record-sizes).
+[See the record size documentation for how record size may impact performance](./ch08-record-sizes.md).
 
 In non-blocking mode, `s2n_send()` will send data from the provided buffer and return the number of
 bytes sent, as long as the socket was able to send at least 1 byte. If no bytes could be sent on the

docs/usage-guide/topics/ch09-certificates.md

@@ -2,7 +2,7 @@
 
 TLS uses certificates to authenticate the server (and optionally the client). The handshake will fail if the client cannot verify the server’s certificate.
 
-Authentication is usually the most expensive part of the handshake. To avoid the cost, consider using [session resumption](./resumption.md) or [pre-shared keys](./preshared_keys.md).
+Authentication is usually the most expensive part of the handshake. To avoid the cost, consider using [session resumption](./ch11-resumption.md) or [pre-shared keys](./ch13-preshared-keys.md).
 
 ## Configuring the Trust Store
 

docs/usage-guide/topics/ch14-early-data.md

@@ -24,7 +24,7 @@ To send early data, your application should call `s2n_send_early_data()` before
 
 `s2n_connection_get_remaining_early_data_size()` can be called to check how much more early data the client is allowed to send. If `s2n_send_early_data()` exceeds the allowed maximum, s2n-tls returns a usage error.
 
-Like other IO functions, `s2n_send_early_data()` can potentially fail repeatedly with a blocking error before it eventually succeeds: see [I/O Functions](./io.md) for more information. An application can stop calling `s2n_send_early_data()` at any time, even if the function has not returned success yet. If `s2n_send_early_data()` does return success, the connection is ready to complete the handshake and begin sending normal data. However, `s2n_send_early_data()` can continue to be called to send more early data if desired.
+Like other IO functions, `s2n_send_early_data()` can potentially fail repeatedly with a blocking error before it eventually succeeds: see [I/O Functions](./ch07-io.md) for more information. An application can stop calling `s2n_send_early_data()` at any time, even if the function has not returned success yet. If `s2n_send_early_data()` does return success, the connection is ready to complete the handshake and begin sending normal data. However, `s2n_send_early_data()` can continue to be called to send more early data if desired.
 
 Once a client finishes sending early data, you should call `s2n_negotiate()` to complete the handshake just as you would for a handshake that did not include early data.
 
@@ -54,7 +54,7 @@ while (s2n_negotiate(client_conn, &blocked) != S2N_SUCCESS) {
 
 To receive early data, your application should call `s2n_recv_early_data()` before it calls `s2n_negotiate()`.
 
-Like other S2N IO functions, `s2n_recv_early_data()` can potentially fail repeatedly with a blocking error before it eventually succeeds: see [I/O Functions](./io.md) for more information. Once `s2n_recv_early_data()` has been called, it must be called until it returns success. If an application stops calling `s2n_recv_early_data()` early, some early data may be left unread and cause later calls to `s2n_negotiate()` to return fatal errors. Calling `s2n_recv_early_data()` again after it returns success is possible but has no effect on the connection.
+Like other S2N IO functions, `s2n_recv_early_data()` can potentially fail repeatedly with a blocking error before it eventually succeeds: see [I/O Functions](./ch07-io.md) for more information. Once `s2n_recv_early_data()` has been called, it must be called until it returns success. If an application stops calling `s2n_recv_early_data()` early, some early data may be left unread and cause later calls to `s2n_negotiate()` to return fatal errors. Calling `s2n_recv_early_data()` again after it returns success is possible but has no effect on the connection.
 
 Once a server has read all early data, you should call `s2n_negotiate()` to complete the handshake just as you would for a handshake that did not include early data.