chore: update documentation URLs to use workspace setting

Replace all docs.rs documentation URLs with documentation.workspace = true
to inherit from the workspace's docs.pezkuwichain.io URL.

pezkuwi/xcm/docs/Cargo.toml

@@ -7,7 +7,7 @@ repository.workspace = true
 authors.workspace = true
 edition.workspace = true
 publish = false
-documentation = "https://docs.rs/xcm-pez-docs"
+documentation.workspace = true
 homepage = { workspace = true }
 
 [dependencies]