markdownlint shows warning on 4-space indent of subsections (expects 2 spaces)

I'm using markdownlint (VS Code plugin) to help me create clean MD documents.  I'm using it as is, without any custom settings.  When I create subsections, TOC includes nested list elements with 4 spaces per indentation level.  And then lint warns me on 4 spaces indentation -- it expects 2 spaces:

```
[markdownlint] MD007/ul-indent: Unordered list indentation [Expected: 2; Actual: 4]
```