- add ToC and anchors for all headings
- move docker bridge settings into "How it works" - it's a rarely used
feature
- highlight a bunch of features, extracting them from obscurely titled
sub-sections of "manual usage"
- basic rendundancy
- adding/removing extra DNS entries
- service hot-swapping
- ability to retain entries for stopped containers
- using a different local domain
- rename remainder of "manual usage" section to "Using weaveDNS
without `weave run`"
- remove "Unregistering" section - it was out of date and is not
covered by the "add/remove" section