Added XML decoder (#1044)

pkg/yqlib/doc/operators/headers/load.md

@@ -0,0 +1,14 @@
+# Load
+
+The `load`/`strload` operator allows you to load in content from another file referenced in your yaml document.
+
+Note that you can use string operators like `+` and `sub` to modify the value in the yaml file to a path that exists in your system.
+
+Use `strload` to load text based content as a string block, and `load` to interpret the file as yaml.
+
+Lets say there is a file `../../examples/thing.yml`:
+
+```yaml
+a: apple is included
+b: cool
+```