Feature Idea: Allow Replacements / Text Transformations

[gohrner]

I helpful feature would be to allow certain text transformations / formatting before adding the matched text to the template.

One example would be escaping for Markdown or URL encoding, such that the added text does not mess up generated links.

(With a Template like [$1]($2), all sorts of characters in the matched text could mess up the result.)

Another example would be text transformation, e.g. I'd like to convert Java package and class names like java.util.List to a Javadoc link like https://docs.oracle.com/javase/8/docs/api/java/util/List.html. I don't see an easy way to do this with the current autolink plugin due to the varying package nesting levels. I'd have to replace an arbitrary number of .s in the matched text with / to properly generate the links.