New ignore option --ignore-code

[davidhrbac]

Would it be possible to to ignore code blocks within the MD file?

Code block might be one line `code` - this might be easy to implement.

There is also multi line code:

```bash
codeline
codeline
```

As you can see there might up to 4 backticks. This might be tricky.

[davidhrbac]

Well, maybe it's not necessary since to code block is excluded from the test right now as seen at https://github.com/lukeapage/node-markdown-spellcheck/blob/master/es6/markdown-parser.js#L13

Am I right?

[mlabieniec]

I am still getting errors from code referenced in language specific code blocks i.e. ```js