Style link by tag

This simple plugin adds a markdown postprocessor which adds data-tags metadata to all internal links in the document. This can then be used in conjunction with CSS snippets to selectively style links based on their tag. For example, say we have the following files

1. file.md

   I am a file, see also [[linked file]].
   

2. linked file.md

   ---
   tags:
     - public
     - foo
   ---
   
   # Title
   
   Foo #bar
   

The the <a> element for [[linked file]] in file.md will have the property data-tags="public foo bar". This can be then used in css, for example

.internal-link[data-tags~="public"] {
  color: red;
}

styles all links resolved to files tagged #public in red.