Module utils

Miscellaneous utilities to incraese comfort. Special thanks to:

• https://github.com/BenjaminRi/Redwood-Wiki/blob/master/src/markdown_utils.rs. Its author authorized the use of this GPL code in this project in https://github.com/raphlinus/pulldown-cmark/issues/507.

• https://gist.github.com/rambip/a507c312ed61c99c24b2a54f98325721. Its author proposed the solution in https://github.com/raphlinus/pulldown-cmark/issues/708.

Structs

• TextMergeStream
  Merge consecutive Event::Text events into only one.
• TextMergeWithOffset
  Merge consecutive Event::Text events into only one with offsets.