Document use and configuration of Web and Web Terminal services

[jovatn]

Infix has a web-service, with a set of (sub?) services related to it (web console, netbrowse and restconf)
Currently there does not seem to be any information on how to use or manage these services, at least not for enable/disable the generic web service or the web console.
(For netbrowse, there is a documentation task (#738), and for restconf some documentation exists in scripting.md.)

  "infix-services:web": {
    "enabled": true,
    "console": {
      "enabled": true
    },
    "netbrowse": {
      "enabled": true
    },
    "restconf": {
      "enabled": true
    }