update doc directory with current state from leap_doc

doc/details/couchdb.md

doc/details/development.md

doc/details/en.haml

doc/details/faq.md

doc/details/under-the-hood.md

doc/details/webapp.md

doc/en.md

doc/guide/commands.md

doc/guide/config.md

doc/guide/en.haml

doc/guide/keys-and-certificates.md

doc/guide/miscellaneous.md

doc/guide/nodes.md

doc/troubleshooting/en.haml

doc/troubleshooting/known-issues.md

doc/troubleshooting/tests.md

doc/troubleshooting/where-to-look.md

doc/tutorials/en.haml

doc/tutorials/quick-start.md

doc/tutorials/single-node.md