refactor: drastically simplify should_add_back_equals logic

src/main.rs

@@ -22,17 +22,12 @@ fn main() {
 }
 
 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 should_add_back_equals = input
+        .find('=')
+        .inspect(|i| {
+            input.remove(*i);
+        })
+        .is_some();
 
     // no need to remove the characters here,
     // as we ignore the them in all other logic already