docshelper: List Chroma lexers
docshelper: List Chroma lexers

Fixes #4554

gohugoio/hugo,anthonyfok/hugo,fedelibre/hugo,mdhender/hugo,anthonyfok/hugo,fedelibre/hugo,mdhender/hugo,fedelibre/hugo,mdhender/hugo,mdhender/hugo,anthonyfok/hugo,fedelibre/hugo,gohugoio/hugo,gohugoio/hugo