Automated developer guide update

Author: schutzbot

docs/developer-guide/02-projects/images/cmds.md

@@ -2,7 +2,7 @@
 
 The following utilities, defined in the `cmd/` directory, are useful for
 development and testing. They **should not** be relied on for production
-purposes. In particular, command line options and default behaviour can change
+purposes. In particular, command line options and default behavior can change
 at any time.
 
 The following are high level descriptions of what some of the utilities can do

docs/developer-guide/02-projects/images/code-manifest-generation.md

@@ -19,7 +19,7 @@ Manifests are generated in two general stages: _Instantiation_ and _Serializatio
       stage-sequences.
 - Serialization: Creates the sequence of stages based on each pipeline and
   produces [`manifest.OSBuildManifest`][godoc-manifest-osbuildmanifest], which
-  is a `[]byte` array with custom un/marshalling methods.
+  is a `[]byte` array with custom unmarshalling/marshalling methods.
   - This stage requires the content specifications resolved from the manifest
     source specifications (package specs, container specs, ostree commit
     specs). See [Resolving Content](#resolving-content).