Improve duffle.json docs (#801)

Fixes #751

cmd/duffle/build.go

@@ -31,9 +31,9 @@ import (
 )
 
 const buildDesc = `
-Builds a Cloud Native Application Bundle (CNAB) given a path to a directory that has a duffle build file (duffle.json).
+Builds a Cloud Native Application Bundle (CNAB) given a path to a directory that has a duffle configuration file (duffle.json).
 
-It builds the invocation images specified in the duffle build file and then creates or updates the bundle in local storage with the latest invocation images.
+It builds the invocation images specified in the duffle configuration file and then creates or updates the bundle in local storage with the latest invocation images.
 `
 
 const (

cmd/duffle/create.go

@@ -20,7 +20,7 @@ For example, 'duffle create foo'  will create a directory structure that looks l
 
     foo/
         |
-        |- duffle.json        # The build definition file
+        |- duffle.json        # The build configuration file
         |
         |- cnab/              # Contains invocation image
                 |

docs/proposal/203-duffle-build.md

@@ -1,5 +1,5 @@
 # Duffle Build
 
-This document describes how `duffle build` works, and how it uses the duffle build file: `duffle.json`.
+This document describes how `duffle build` works, and how it uses the duffle build configuration file: `duffle.json`.
 
-`duffle build` take a path to a directory that contains a duffle build file (`duffle.json`) to build a Cloud Native Application Bundle (CNAB). In the process, it also builds all of the invocation images specified in the duffle build file.
+`duffle build` take a path to a directory that contains a duffle build configuration file (`duffle.json`) to build a Cloud Native Application Bundle (CNAB). In the process, it also builds all of the invocation images specified in the duffle build configuration file.

pkg/duffle/manifest/create.go

@@ -33,7 +33,7 @@ CMD ["/cnab/app/run"]
 
 const schemaVersion = "v1.0.0-WD"
 
-// Scaffold takes a path and creates a minimal duffle manifest (duffle.json)
+// Scaffold takes a path and creates a minimal duffle configuration file (duffle.json)
 //  and scaffolds the components in that manifest
 func Scaffold(path string) error {
 	name := filepath.Base(path)