Update contribution docs (#309)

Update contribution docs

.gitignore

@@ -1,4 +1,5 @@
 /*coverage.out
+/chezmoi
 /dist
 /goreleaser/goreleaser.host.yaml
 /goreleaser/snap.login

.travis.yml

@@ -14,12 +14,7 @@ env:
 
 install:
 - go mod download
-- GO111MODULE=off go get golang.org/x/tools/cmd/cover
-- GO111MODULE=off go get github.com/golangci/golangci-lint/cmd/golangci-lint
-- GO111MODULE=off go get github.com/mattn/goveralls
-- GO111MODULE=off go get github.com/wadey/gocovmerge
-- GO111MODULE=off go get mvdan.cc/gofumpt
-- GO111MODULE=off go get mvdan.cc/gofumpt/gofumports
+- make install-tools
 
 script:
 - make all

Makefile

@@ -33,6 +33,16 @@ goreleaser/goreleaser.host.yaml: goreleaser/goreleaser.yaml.tmpl internal/genera
 html-coverage:
 	go tool cover -html=coverage.out
 
+.PHONY: install-tools
+install-tools:
+	GO111MODULE=off go get -u \
+		golang.org/x/tools/cmd/cover \
+		github.com/golangci/golangci-lint/cmd/golangci-lint \
+		github.com/mattn/goveralls \
+		github.com/wadey/gocovmerge \
+		mvdan.cc/gofumpt \
+		mvdan.cc/gofumpt/gofumports
+
 .PHONY: lint
 lint:
 	go vet ./...

docs/CONTRIBUTING.md

@@ -1,13 +1,60 @@
 # Contributing
 
-chezmoi development happens on Github. When contributing, please first [open an
+* [Getting started](#getting-started)
+* [Developing locally](#developing-locally)
+* [Contributing changes](#contributing-changes)
+* [Managing releases](#managing-releases)
+* [Packaging](#packaging)
+
+## Getting started
+
+chezmoi is written in [Go](https://golang.org) and development happens on
+[GitHub](https://github.com). The rest of this document assumes that you've
+checked out chezmoi locally.
+
+## Developing locally
+
+chezmoi is a standard Go project, using standard Go tooling, with a few extra
+tools. Install these extra tools with:
+
+    make install-tools
+
+Build chezmoi:
+
+    go build github.com/twpayne/chezmoi
+
+Run all tests:
+
+    go test github.com/twpayne/chezmoi/...
+
+Run chezmoi:
+
+    go run github.com/twpayne/chezmoi
+
+## Contributing changes
+
+Bug reports, bug fixes, and documentation improvements are always welcome.
+Please [open an issue](https://github.com/twpayne/chezmoi/issues/new) or [create
+a pull request](https://help.github.com/en/articles/creating-a-pull-request)
+with your report, fix, or improvement.
+
+If you want to make a more significant change, please first [open an
 issue](https://github.com/twpayne/chezmoi/issues/new) to discuss the change that
-you want to make. Bug reports and documentation improvements are particularly
-welcome.
+you want to make. Dave Cheney gives a [good
+rationale](https://dave.cheney.net/2019/02/18/talk-then-code) as to why this is
+important.
 
 All changes are made via pull requests. In your pull request, please make sure
 that:
 
+* Your code is correctly formatted, according to
+  [gofumports](https://mvdan.cc/gofumpt/gofumports). You can ensure this by
+  running `make format`.
+
+* Your code passes [`go vet`](https://golang.org/cmd/vet/) and
+  [`golangci-lint`](https://github.com/golangci/golangci-lint). You can ensure
+  this by running `make lint`.
+
 * The commit messages match chezmoi's convention, specifically that they being
   with a capitalized verb in the imperative and give a short description of what
   the commit does. Detailed information or justification can be optionally
@@ -21,7 +68,7 @@ that:
 
 * The branch applies cleanly to `master`.
 
-## Release management
+## Managing releases
 
 Releases are managed with [goreleaser](https://goreleaser.com/).