- replace anyhow with thiserror

src/error.rs

@@ -0,0 +1,14 @@
+use thiserror::Error;
+
+
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("io error: {0}")]
+    IO(#[from] std::io::Error),
+    #[error("could not parse color: {0}")]
+    ColorParse(String),
+    #[error("colorcet error: {0}")]
+    ColorCet(#[from] colorcet::ColorcetError),
+    #[error("could not covert ColorMap into LinearGradient")]
+    Conversion
+}