Initialize Rust GPUI browser shell

crates/ely_domain/src/error.rs

@@ -0,0 +1,13 @@
+use thiserror::Error;
+
+#[derive(Clone, Debug, Error, Eq, PartialEq)]
+pub enum DomainError {
+    #[error("{field} cannot be empty")]
+    EmptyField { field: &'static str },
+
+    #[error("invalid URL: {value}")]
+    InvalidUrl { value: String },
+
+    #[error("invalid command query")]
+    InvalidCommand,
+}