fenced code blocks should have a language specified code example

Example 1: links should be surrounded by blank lines readme.md error

# Heading 1

### Heading 3

We skipped out a 2nd level heading in this document

Example 2: links should be surrounded by blank lines readme.md error

# Heading 1

## Heading 2

### Heading 3

#### Heading 4

## Another Heading 2

### Another Heading 3