yq/Upgrade Notes

# New Features
  - Keeps yaml comments and formatting (string blocks are saved, number formatting is preserved, so it won't drop off trailing 0s for values like 0.10, which is important when that's a version entry )
  
  - Handles anchors! (doc link)
  - Can specify yaml tags (e.g. !!int), quoting values no longer sufficient, need to specify the tag value instead.
  - Can print out matching paths and values when splatting (doc link)
  - JSON output works for all commands! Yaml files with multiple documents are printed out as one JSON document per line. 
  - Deep splat (**) to match arbitrary paths, (doc link)


# Breaking changes

## Update scripts file format has changed to be more powerful. 
Comments can be added, and delete commands have been introduced.

## Reading and splatting, matching results are printed once per line.
  e.g:

```json
parent:
  childA: 
    no: matches here
  childB:
    there: matches
    hi: no match
    there2: also matches
```

yq r sample.yaml 'parent.*.there*'

old
```yaml
- null
- - matches
  - also matches
```

new
```yaml
matches
also matches
```

and you can print the matching paths:

yq r --printMode pv sample.yaml 'parent.*.there*'

```yaml
parent.childB.there: matches
parent.childB.there2: also matches
```

# Merge command
- New flag 'autocreates' missing entries in target by default, new flag to turn that off.