Add preserve-order duplicate removal one-liner

@@ -282,3 +282,9 @@ list1, list2 = zip(*list_of_tuples)

s = s.replace(char, "")

```

**Example:** `"apple", "p" → "ale"`

## Remove duplicates from list while preserving order

```python

seen = set(); result = [x for x in my_list if not (x in seen or seen.add(x))]

```

**Example:** `[1, 2, 2, 3, 1] → [1, 2, 3]`