Adding another xml test; spelling fixes

pkg/yqlib/doc/operators/pick.md

@@ -13,7 +13,7 @@ myMap:
   cat: meow
   dog: bark
   thing: hamster
-  hamster: squeek
+  hamster: squeak
 ```
 then
 ```bash
@@ -22,7 +22,7 @@ yq '.myMap |= pick(["hamster", "cat", "goat"])' sample.yml
 will output
 ```yaml
 myMap:
-  hamster: squeek
+  hamster: squeak
   cat: meow
 ```
 

pkg/yqlib/doc/usage/xml.md

@@ -128,6 +128,25 @@ zoo:
     - cat
 ```
 
+## Parse xml: force all as an array
+Because of the way yq works, when updating everything you need to update the children before the parents. By default `..` will match parents first, so we reverse that before updating.
+
+Given a sample.xml file of:
+```xml
+<zoo><thing><frog>boing</frog></thing></zoo>
+```
+then
+```bash
+yq -oy '([..] | reverse | .[]) |= [] + .' sample.xml
+```
+will output
+```yaml
+- zoo:
+    - thing:
+        - frog:
+            - boing
+```
+
 ## Parse xml: attributes
 Attributes are converted to fields, with the default attribute prefix '+'. Use '--xml-attribute-prefix` to set your own.