Getting started can be quite a steep learning curve to understand the various files and structure of the HA system. I’ve been using hass.io for a few months, and I only recently started looking at the known_devices.yaml file. Its not something that will help you in the near term. Maybe later when you advance to location tracking and zones and therefore to the known_devices.yaml file (which is showing devices on my home network, not my home automation stuff). So, if I were you, forget that file for a while.
With “discovery” there is nothing added to any yaml files for you (that I’m aware of). Discovery simply means HA will automatically load the necessary components to support the things it automatically discovers in your environment, without you having to first put something in your configuration.yaml file. If you need to manually adjust settings for something that is auto discovered, you manually add the necessary code to your configuration.yaml file.
For example, initially my Harmony Hub was discovered. It shows up in the default frontend as “remote” with an on/off toggle. There was nothing in configuration.yaml. On my web frontend, when I click the <>
button as others have said, it is listed there under “Current entities”, as “remote.harmony_hub” along with its current state and attributes. Note, your devices, whether discovered or manually configured by you, are “entities” in this list. Remember this <>
page, you will visit it often.
As I’ve progressed in configuring my setup my Harmony Hub now shows up in my frontend as “Harmony Hub”, with a drop-down list of all my Harmony Activities, in a group I call Living Room. I used a lot of borrowed code from the forums to get here. I have entries in configuration.yaml, customize.yaml, customze_glob.yaml, automations.yaml, and groups.yaml to get to where it is today. I created all of those files except for configuration.yaml.
Reorganizing your web frontend requires manually typing the names of the entities you want in to the appropriate sections of your configuration.yaml file (or groups.yaml if you decide to split your configuration). It’s a process of a manual coding.
I recommend going to the Docs page and working your way down the links on the right side one at a time starting with the Configuration section. You may not actually do anything, or be ready to do anything with each section you read, but hopefully you’ll begin to see how things interrelate as you process through things. I found terminology to not always be clear, so reading through the docs helps you to see how the terms are being used and suss out information that’s not always obvious.
And keep searching and posting in the forums. It helps with sanity when you’re tired of banging your head on the wall
Have fun!
btw, you’ll spend most if not all your time in the config folder working on yaml files in there. I’ve done almost nothing in the other folders so far.
[edit]
There is quite a bit of help here and on the web, but it appears that only a subset works for hass.io.
To clarify, almost all of the documentation and forums apply to hass.io, IF it is talking about how to configure your home automation devices in HA, or modify the frontend. hass.io is just one way of installing HA, so if the documents you’re reading are about the underlying OS of your setup, or making changes at a low level, that’s where you need to question whether it applies to your hass.io implementation. hass.io is designed to manage the underlying OS environment, and therefore does have restrictions at that level. However, if your focus is on getting your automation devices to work within HA, then all that documentation applies. There is a special “hass.io” section in the forum, but don’t think that’s the only section that applies to you. If anything, the “Installation” section is the one you may want to avoid, as you’ve chosen hass.io as your installation.