Comments without new line above result in babel error

[DavidWells]

Ref: #184 (comment)

It looks like this is working for most comments but I just ran into an error with comments in MD

The markdown looks like this:

# login

<!-- AUTO-GENERATED-CONTENT:START (TOC) -->
- [login](#login-1)
<!-- AUTO-GENERATED-CONTENT:END -->

It replaces the top <!-- AUTO-GENERATED-CONTENT:START (TOC) --> correctly but passes over the second comment <!-- AUTO-GENERATED-CONTENT:END --> because there is no newline

This results in a babel error:

Error: Module build failed (from ./node_modules/babel-loader/lib/index.js):
SyntaxError: Unexpected token (15:1)

  13 | <MDXTag name="li" components={components} parentName="ul">
  14 | <MDXTag name="p" components={components} parentName="li"><MDXTag name="a" components={components} parentName="p" props={{"href":"#login-1"}}>{`login`}</MDXTag></MDXTag>
> 15 | <!-- AUTO-GENERATED-CONTENT:END -->
     |  ^
  16 | </MDXTag>
  17 | </MDXTag>
  18 | {/* AUTO-GENERATED-CONTENT:START (GENERATE_COMMANDS_DOCS) */}

I was able to work around it by adding a newline after the list. This markdown works because there is a newline after the list

# login

<!-- AUTO-GENERATED-CONTENT:START (TOC) -->
- [login](#login-1)

<!-- AUTO-GENERATED-CONTENT:END -->

Is there a way to support this without the newline? Thanks!

Loving MDX btw it's freaking sweet

[silvenon]

Resolved with #260 and released in v0.15.3-0.