Buckets Inside Buckets example needs .keyword

[mikepedroza]

https://www.elastic.co/guide/en/elasticsearch/guide/master/_buckets_inside_buckets.html#_buckets_inside_buckets
The following example won't work unless you specify the .keyword on color/price/make.

GET /cars/transactions/_search
{
"size" : 0,
"aggs": {
"colors": {
"terms": {
"field": "color"
},
"aggs": {
"avg_price": {
"avg": {
"field": "price"
}
},
"make": {
"terms": {
"field": "make"
}
}
}
}
}
}

[mikepedroza]

Also.. it would be good to explain on the first example using .keyword 1) why it's needed & 2) how the auto-index generation automatically adds it to the text fields.