expand the tags in modules in the notes branch

[vladak]

The tags (e.g. #source) should be expanded in the individual modules in the notes branch. Needed for direct links to modules so that the links work (e.g. toupper.md).

[vladak]

The plugins used to resolving custom tags are processed only in markdown-include's compileFiles() which needs JSON file as input. Either we will construct the JSON file on the fly for each processed file or modify markdown-include to allow the processing directly (last commit date is 2016 so it is not clear what are the chances of accepting pull requests).