Add regex support for filenames

[matthewturner]

This is a very rudimentary implementation of allowing regex pattern matching in filenames (inspired by #723) for the TOC in case anyone can use it as a starting point.

It allows the user to specify the following to apply to all .md files matching the pattern:

// In your settings.json
"markdown.extension.toc.omittedFromToc": {
  "*.md": [
      "# Introduction",
      "## Also omitted",
  ],

[yzhang-gh]

Thanks for your interest and also sorry for forgetting to reply. As said yesterday in #1496 (comment) (may need translation), I do not have enough time to keep developing this repository and decided to leave it as is except for severe bugs. Please feel free to fork and modify for your use.