hex colors in readme broken

[SimonSiefke]

A Readme.md like this:

## Configure the background:

```json
{
  "myExtension.style": {
    "html": {
      "background": "linear-gradient(45deg, #141414 25%, transparent 25%, transparent 75%, #141414 75%, #141414), linear-gradient(45deg, #141414 25%, transparent 25%, transparent 75%, #141414 75%, #141414)"
    }
  }
}
`` `

gets transformed into

## Configure the background:

```json
{
  "myExtension.style": {
    "html": {
      "background": "linear-gradient(45deg, [#141414](https://github.com/user/myExtension/issues/141414) 25%, transparent 25%, transparent 75%, [#141414](https://github.com/user/myExtension/issues/141414) 75%, [#141414](https://github.com/user/myExtension/issues/141414)), linear-gradient(45deg, [#141414](https://github.com/user/myExtension/issues/141414) 25%, transparent 25%, transparent 75%, [#141414](https://github.com/user/myExtension/issues/141414) 75%, [#141414](https://github.com/user/myExtension/issues/141414))"
    }
  }
}
`` `

I guess this is because of #345

[oliversalzburg]

IMHO, PR #345 was completely broken and shouldn't have been merged. It doesn't take into account color codes, as reported by this issue, but it also completely ignored code blocks and fixed-width spans.

The cases where this is needlessly broken seem to dramatically outnumber the cases where it has a beneficial effect. I will open a PR to revert this change.

The user in this ticket might have been able to work around the issue with --no-gitHubIssueLinking though.

[joaomoreno]

Duplicate of #322