Updating `feat-2.0_docs` with changes from `dev`

This PR refreshes our Condor branch with all changes from dev that have occurred since the prior update.

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(Delete any that aren't relevant)

[x] Docs are successfully building - yarn install && yarn run build.
[x] For new internal links I used relative file paths (with .md extension) - e.g. ../../faq/faq-general.md - instead of introducing absolute file path, or relative/absolute URL.
[x] All external links have been verified with yarn run check:externals.
[x] My changes follow the Casper docs style guidelines.
[x] All technical procedures have been tested (if you want help with this, mention it in Reviewers).
[x] If structural changes are introduced (not just content changes), cross-broswer testing has been completed.

@ipopescu

casper-network / docs