Heading Blank Lines: Make Sure Tags on The Line Before a Heading Gets a Blank Line Added when Bottom=false

[pjkaufman]

Fixes #993

There was an issue where Bottom=false and the line before a heading had a # in it.
For example:

# Heading 1
Lorem ipsum.

## Heading 2
Woah, cool text here. #reallycool
## Heading 3

would not get changed.

After the change it now looks like:

# Heading 1
Lorem ipsum.

## Heading 2
Woah, cool text here. #reallycool

## Heading 3

Changes Made:

• Added a test for the scenario in question
• Updated the regex for when Bottom=false to make sure that it only does not allow a line to start with # for adding a blank line before a heading