Migration: Created en and fr versions of all eng and fra files and set canonical rel of eng and fra files to en and fr (to assist search engines with the transition)

This work is part of moving from -eng and -fra filename suffixes to -en and -fr suffixes. This is being done to align with other languages and the HTML5 approach to language identification (2 letters instead of 3 wherever possible).

The duplication is necessary for now to assist search engines with the transition to ensure current search results aren't diminished significantly. GitHub doesn't support 301 redirects so the canonical rel is the next best thing for helping search engines with the transition (meta refresh and 404 pages are not helpful to search engines).