Add linting instructions to Developer's Guide

Also add documentation link.

Makefile

@@ -75,6 +75,7 @@ lint:
 
 HAS_DEP          := $(shell $(CHECK) dep)
 HAS_GOLANGCI     := $(shell $(CHECK) golangci-lint)
+HAS_GOIMPORTS    := $(shell $(CHECK) goimports)
 
 .PHONY: build-drivers
 build-drivers:
@@ -88,5 +89,13 @@ ifndef HAS_DEP
 endif
 ifndef HAS_GOLANGCI
 	curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(GOPATH)/bin
+endif
+ifndef HAS_GOIMPORTS
+	go get -u golang.org/x/tools/cmd/goimports
 endif
 	dep ensure -vendor-only -v
+
+.PHONY: goimports
+goimports:
+	find . -name "*.go" | fgrep -v vendor/ | xargs goimports -w -local github.com/deislabs/duffle
+

docs/README.md

@@ -11,4 +11,5 @@ The following documentation is available:
     3. [Duffle Build](./proposal/203-duffle-build.md)
     4. [Duffle Export/Import](./proposal/204-export-import.md)
 3. Developer Information
-    1. [Debugging](debugging.md)
+    1. [Developer's Guide](developing.md)
+    2. [Debugging Duffle using VS Code](debugging.md)

docs/developing.md

@@ -8,23 +8,22 @@ $ go get -d github.com/deislabs/duffle/...
 $ cd $(go env GOPATH)/src/github.com/deislabs/duffle
 ```
 
-## Building
-
 ### Prerequisites
 You need:
 * A working Go 1.11.4 (or later) environment
 * make
 
-Before you start, issue:
+Before you start working with the code, issue:
 ```console
 $ make bootstrap
 ```
 
-Then, to build `duffle`, issue:
+## Building
+
+To build `bin/duffle`, issue:
 ```console
 $ make build
 ```
-The resultant binary is placed in `bin/duffle`.
 
 If you want to install `duffle`, issue:
 ```console
@@ -38,6 +37,18 @@ To run the tests, issue:
 $ make test
 ```
 
+## Linting
+
+To lint the code, issue:
+```console
+$ make lint
+```
+
+If this detects that some imports need re-organising (errors like "File is not `goimports`-ed"), issue:
+```console
+$ make goimports
+```
+
 ## Debugging
 
 For instructions on using VS Code to debug the Duffle binary, see [the debugging document](debugging.md).