Added XML decoder (#1044)

pkg/yqlib/doc/operators/create-collect-into-object.md

@@ -0,0 +1,82 @@
+# Create, Collect into Object
+
+This is used to construct objects (or maps). This can be used against existing yaml, or to create fresh yaml documents.
+
+## Collect empty object
+Running
+```bash
+yq eval --null-input '{}'
+```
+will output
+```yaml
+{}
+```
+
+## Wrap (prefix) existing object
+Given a sample.yml file of:
+```yaml
+name: Mike
+```
+then
+```bash
+yq eval '{"wrap": .}' sample.yml
+```
+will output
+```yaml
+wrap:
+  name: Mike
+```
+
+## Using splat to create multiple objects
+Given a sample.yml file of:
+```yaml
+name: Mike
+pets:
+  - cat
+  - dog
+```
+then
+```bash
+yq eval '{.name: .pets.[]}' sample.yml
+```
+will output
+```yaml
+Mike: cat
+Mike: dog
+```
+
+## Working with multiple documents
+Given a sample.yml file of:
+```yaml
+name: Mike
+pets:
+  - cat
+  - dog
+---
+name: Rosey
+pets:
+  - monkey
+  - sheep
+```
+then
+```bash
+yq eval '{.name: .pets.[]}' sample.yml
+```
+will output
+```yaml
+Mike: cat
+Mike: dog
+Rosey: monkey
+Rosey: sheep
+```
+
+## Creating yaml from scratch
+Running
+```bash
+yq eval --null-input '{"wrap": "frog"}'
+```
+will output
+```yaml
+wrap: frog
+```
+