Add FontAwesome support and usage instructions

[rohitg00]

• styles/chmduquesne.tex

  • Add \usesymbols[fontawesome] and \def\fa#1{\symbol[fontawesome][#1]} to enable FontAwesome icons.

• Makefile

  • Add mtxrun --script fonts --reload to the pdf target to reload fonts.

• markdown/resume.md

  • Add examples of using FontAwesome icons in the markdown content.

• README.md

  • Add a section explaining how to use FontAwesome icons in the markdown content.

[rohitg00]

Proposed solution for https://github.com/mszep/pandoc_resume/issues/57