Add device storage information

[kimdv]

This can be used to add sensors for storage information.
And also add automation for storage warnings etc

[Kane610]

Awesome

[Kane610]

Anything else you're planning to do before I do a new release?

[kimdv]

Yes, maybe I will add

"temperatures": [
                {
                    "name": "CPU",
                    "type": "cpu",
                    "value": 66.0
                },
                {
                    "name": "Local",
                    "type": "board",
                    "value": 48.75
                },
                {
                    "name": "PHY",
                    "type": "board",
                    "value": 50.25
                }
            ],

That is taken from my Dream Machine SE

[Kane610]

Yes, maybe I will add

"temperatures": [
                {
                    "name": "CPU",
                    "type": "cpu",
                    "value": 66.0
                },
                {
                    "name": "Local",
                    "type": "board",
                    "value": 48.75
                },
                {
                    "name": "PHY",
                    "type": "board",
                    "value": 50.25
                }
            ],

That is taken from my Dream Machine SE

Alright. I'll wait for your next PR before publishing next release