Merge branch 'styles' into gh-pages

[cc-by-human]: https://creativecommons.org/licenses/by/4.0/

[cc-by-legal]: https://creativecommons.org/licenses/by/4.0/legalcode

[concept-maps]: http://swcarpentry.github.io/instructor-training/08-memory/

[concept-maps]: http://carpentries.github.io/instructor-training/05-memory/

[contact]: mailto:lessons@software-carpentry.org

[contrib-covenant]: http://contributor-covenant.org/

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[cran-stringr]: https://cran.r-project.org/web/packages/stringr/index.html

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[importer]: http://import.github.com/new

[importer]: https://github.com/new/import

[jekyll-collection]: https://jekyllrb.com/docs/collections/

[jekyll-install]: https://jekyllrb.com/docs/installation/

[jekyll-windows]: http://jekyll-windows.juthilo.com/