feat: ignore and add back single equal sign

more than one is likely a user mistake and a panic still makes sense

should also add back '&' in the same way, if applicable

src/main.rs

@@ -18,9 +18,33 @@ fn main() {
         }
     };
 
+    println!("{}", parse_and_calc_humanreadable(input));
+}
+
+pub fn parse_and_calc_humanreadable(mut input: String) -> String {
+    let should_add_back_equals = if let Some((i, _)) = input
+        .chars()
+        .enumerate()
+        .filter(|(_, c)| !matches!(c, ' ' | '&' | '\n'))
+        .find(|(_, c)| *c == '=')
+    {
+        input.remove(i);
+        true
+    } else {
+        false
+    };
+
     let result = parse_and_calc(&input);
 
-    println!("{result:.0$}", get_significant_digits(&result));
+    format!(
+        "{0}{result:.1$}",
+        if should_add_back_equals { "= " } else { "" },
+        get_significant_digits(&result),
+    )
+}
+#[test]
+fn test_equals_readdition() {
+    assert_eq!(parse_and_calc_humanreadable(" = 11".into()), "= 11");
 }
 
 pub fn parse_and_calc(s: &str) -> Float {