This rule is triggered when the symbols used in the document for unordered
list items do not match the configured unordered list style:

```markdown
* Item 1
+ Item 2
- Item 3
```

To fix this issue, use the configured style for list items throughout the
document:

```markdown
* Item 1
* Item 2
* Item 3
```

The configured list style can ensure all list styling is a specific symbol
(`asterisk`, `plus`, `dash`), ensure each sublist has a consistent symbol that
differs from its parent list (`sublist`), or ensure all list styles match the
first list style (`consistent`).

For example, the following is valid for the `sublist` style because the
outer-most indent uses asterisk, the middle indent uses plus, and the inner-most
indent uses dash:

```markdown
* Item 1
  + Item 2
    - Item 3
  + Item 4
* Item 4
  + Item 5
```

Rationale: Consistent formatting makes it easier to understand a document.