Change highlighter to support typescript

[aurelien-baudet]

Coderay doesn't seem to handle TypeScript. Use highlight.js instead ?

/!\ Ensure that code source extensions are still working

[aurelien-baudet]

CodeRay doesn't support typescript for now.
Highlight.js can support typescript but doesn't support other features (line numbers and our custom extensions, console source codes, pdf format, ...).

Several possibilities:

1. Add a CodeRay extension to support typescript or make a PR (see https://github.com/rubychan/coderay/blob/master/lib/coderay/scanners/java_script.rb)
2. Indicate that code is JavaScript instead of TypeScript
3. Use Highlight.js but update it to support custom extensions, line numbers and other features
4. Use another syntax highlighter ? It must be compatible with asccidoctorj
5. Replace use of maven by a docker image that uses ruby instead of java in order to use another syntax highlighter (ensure that support of another syntax highlighter still supports all existing features). For the moment only pygments could be used.