doc: extract docstrings from zpm commands
doc: add anchors for zpm commands
commands: expand docstrings slightly
deploy: link to Swift command line tool
doc: shorten main page title
doc: add introduction document

This describes how to bundle and deploy a very simple "Hello World"
program. It should of course be extended and probably split into more
logical sections.
Merge pull request #39 from mgeisler/expand-doc

Expand documentation