Documentation: custom commands json

Hi,

does documentation how to define custom commands exist and I cannot find or it does not exit? I spend some time searching for it and browsing through the code to find information. I bet I am not the only one.
This would have been enough:
# Custom commands json
## Command list

```
[
{
"description": "List all files",
"cmd": [
"ls",
"-ls"
]
}
]
```
## Command list with submenu

```
[
{
"description": "List all files",
"cmd": [
"ls",
"-ls"
]
},
{
"type": "menu",
"description": "Remote commands",
"items": [
{
"description": "ssh to host",
"cmd": [
"ssh",
"hostname"
]
}
]
}
]
```