fix: correct domain from pezkuwi.io to pezkuwichain.io

The pezkuwi.io domain does not exist. All references have been
updated to the correct pezkuwichain.io domain.

Fixed files:
- subxt examples (rpc.pezkuwichain.io)
- subxt lib.rs documentation
- contracts fixtures (homepage, authors email)
- CHANGELOG.md (zagros-rpc.pezkuwichain.io)

vendor/pezkuwi-subxt/subxt/src/lib.rs

@@ -198,7 +198,7 @@ pub mod ext {
 ///
 /// ```rust,ignore
 /// #[pezkuwi_subxt::subxt(
-///     runtime_metadata_insecure_url = "wss://rpc.pezkuwi.io:443"
+///     runtime_metadata_insecure_url = "wss://rpc.pezkuwichain.io:443"
 /// )]
 /// mod pezkuwi {}
 /// ```
@@ -374,7 +374,7 @@ pub mod ext {
 ///
 /// ```rust,ignore
 /// #[pezkuwi_subxt::subxt(
-///     runtime_metadata_insecure_url = "wss://rpc.pezkuwi.io:443",
+///     runtime_metadata_insecure_url = "wss://rpc.pezkuwichain.io:443",
 ///     unstable_metadata
 /// )]
 /// mod pezkuwi {}