move to use "conduit_yaml" in docs

[cyrush]

Audit examples and change to use yaml output for schema details in examples.

We need "conduit_yaml" rep that includes details to replace the "conduit_json" output.

Also, "conduit_json" formatting is a little strange here:

  "x": 
{
"dtype":"float64",
"number_of_elements": 5,
"offset": 0,
"stride": 24,
"element_bytes": 8,
"endianness": "little"
, "value": [1.0, 1.0, 1.0, 1.0, 1.0]},
  "y": 
{
"dtype":"float64",
"number_of_elements": 5,
"offset": 8,
"stride": 24,
"element_bytes": 8,
"endianness": "little"
, "value": [2.0, 2.0, 2.0, 2.0, 2.0]},
  "z": 
{
"dtype":"float64",
"number_of_elements": 5,
"offset": 16,
"stride": 24,
"element_bytes": 8,
"endianness": "little"
, "value": [3.0, 3.0, 3.0, 3.0, 3.0]}
}

The logic that fuses the schema details with the values needs to be adjusted.

(from https://llnl-conduit.readthedocs.io/en/latest/blueprint.html#top-level-blueprint-interface)