corrected doc (#2368)

Signed-off-by: swastik959 <Sswastik959@gmail.com>

docs/reference/func_yaml.md

@@ -16,23 +16,25 @@ such as the function name, and the image name.
 
 The following fields are used in `func.yaml`.
 
+
+### `build`
+
+Specifies how to build the fuction. Possible values are "local" to build on your local
+computer, or "git" to build on the cluster by pulling function source code from a git
+repository.
+
 ### `builderImages`
 
 Defines the builder images to use by builder implementations in lieu of the defaults.
 They key is the builder's short name.  For example:
 
 ```
-builderImages:
-	pack: example.com/user/my-pack-node-builder
-  s2i: example.com/user/my-s2i-node-builder
+build:
+  builderImages:
+	  pack: example.com/user/my-pack-node-builder
+    s2i: example.com/user/my-s2i-node-builder
 ```
 
-### `build`
-
-Specifies how to build the fuction. Possible values are "local" to build on your local
-computer, or "git" to build on the cluster by pulling function source code from a git
-repository.
-
 ### `git`
 
 If using a `git` build strategy, this field is used to specify the git URL as well