text: Title: Incorrect indent for multiline string within list
  Body: **Describe the bug**
  A clear and concise description of what the bug is.
  
  **To Reproduce**
  
  Input:
  
  ```python
  def test_snapshot(snapshot):
      data = {
          "key": [
              "line 1\nline 2"
          ]
      }
      assert data == snapshot
  ```
  
  ```
  pytest --snapshot-update
  ```
  
  Output:
  
  ```ambr
  # name: test_snapshot
    <class 'dict'> {
      'key': <class 'list'> [
    '
          line 1
          line 2
        ',
      ],
    }
  ---
  ```
  
  **Expected behavior**
  
  The multiline string `'` should be indented:
  
  ```ambr
  # name: test_snapshot
    <class 'dict'> {
      'key': <class 'list'> [
        '
          line 1
          line 2
        ',
      ],
    }
  ---
  ```
  
  syrupy==0.6.1
  
  