Replace extract_figures.py with Javacript

Demo at https://github.com/swcarpentry/lesson-example/pull/132/.

add keyboard key style

Fix concept-maps link

Close #176

Fix github-importer link

Close #177

Add "Offline" Capable

This is based on https://github.com/swcarpentry/lesson-example/pull/127/.

Fix episode nav wrapping

By doing this, when a page is heavily zoomed in (e.g. 500%) the navbar
icons stay in the same row, rather than breaking onto two different rows.

Load methods package

Building `md` from `Rmd` in a script like this will break if the `methods` package is not called and the code includes class object routines. See https://github.com/r-spatial/sf/issues/478

SWC uses block inline attribute lists for e.g. code blocks, but I think this HTML tag is much simpler and more understandable than <pre>*Enter*{:.keyboard} ...</pre>

Output episode figures in correct order

Add Library Carpentry SVG logo

Fix logo at navbar

by run

~~~
$ find _includes -type f -exec sed -i "s/page.carpentry/site.carpentry/g" {} \;
$ find _layouts -type f -exec sed -i "s/page.carpentry/site.carpentry/g" {} \;
$ find _extras -type f -exec sed -i "s/page.carpentry/site.carpentry/g" {} \;
$ find _episodes -type f -exec sed -i "s/page.carpentry/site.carpentry/g" {} \;
$ find bin -type f -exec sed -i "s/page.carpentry/site.carpentry/g" {} \;
$ find assets -type f -exec sed -i "s/page.carpentry/site.carpentry/g" {} \;
~~~

Unify Library Carpentry logo

Close #155

Link LC as for SWC and DC

See https://github.com/swcarpentry/workshop-template/issues/410

This reverts commit 1e56203d.

Add all in one lesson build with Javascript

Make challenges and discussion visibles

This is based on
https://github.com/swcarpentry/instructor-training/pull/437/files and
https://github.com/swcarpentry/instructor-training/pull/439/files,
both write by @ErinBecker.

Updated CONDUCT.md

Rebased of https://github.com/swcarpentry/lesson-example/pull/116/.

Thanks to @tracyteal.

Suggest template language