Improve installation tutorials

• Database Lab, Joe tutorial: warn to set up accessHost for Database Lab configurations: Host which will be specified in clone connection info: accessHost: "localhost"
• clarify why tokens are -- hard to understand that we need to. Where to take them. Improve the doc and improve the config
• Add Joe configuration in the console to Joe tutorial. Enable history by default.
• dbname has to be test if we want to continue the dblab tutorial.
• comment out the Slack section from the config by default.
  • It's inconvenient to delete (or comment out) the section which is not necessary (need only Web UI)