Added error example

examples/errors.rs

@@ -0,0 +1,35 @@
+// Basic Gura parser usage example
+use gura::{errors::Error, parse};
+
+fn main() {
+    let gura_string = r##"
+# This is a Gura document.
+title: "Gura Example"
+
+some_invalid: $non_existent_var 
+"##;
+
+    // Parse: transforms a Gura string into a dictionary
+    match parse(&gura_string) {
+        Ok(parsed) => {
+            println!("Title -> {}", parsed["title"]);
+        }
+        Err(e) => {
+            println!("Error: {}", e); // Error implements fmt::Display
+
+            match e.kind {
+                Error::ParseError => println!("Syntax is wrong!"),
+                Error::VariableNotDefinedError => println!("A non defined variable was used! "),
+                Error::InvalidIndentationError => println!("Indentation is invalid!"),
+                Error::DuplicatedVariableError => {
+                    println!("A variable was defined more than once!")
+                }
+                Error::DuplicatedKeyError => println!("A key was defined more than once!"),
+                Error::FileNotFoundError => println!("An imported file does not exist!"),
+                Error::DuplicatedImportError => {
+                    println!("The same Gura file was imported more than once!")
+                }
+            }
+        }
+    }
+}