improvement: automate changelog management (#786)

.chglog/CHANGELOG.tpl.md

@@ -0,0 +1,66 @@
+# Change Log
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/) and this
+project adheres to [Semantic Versioning](http://semver.org/).
+
+{{ if .Versions -}}
+<a name="unreleased"></a>
+## [Unreleased]
+{{ if .Unreleased.CommitGroups -}}
+{{ range .Unreleased.CommitGroups -}}
+{{ .Title }}:
+{{ range .Commits -}}
+{{- if .Subject -}}
+- {{ if .Scope }}**{{ .Scope }}:** {{ end }}{{ .Subject }}
+{{- end -}}
+{{ end }}
+{{ end -}}
+{{ else }}
+{{ range .Unreleased.Commits -}}
+{{- if .Subject -}}
+- {{ if .Scope }}**{{ .Scope }}:** {{ end }}{{ .Subject }}
+{{- end -}}
+{{ end }}
+{{ end -}}
+{{ end -}}
+
+{{ range .Versions }}
+<a name="{{ .Tag.Name }}"></a>
+## {{ if .Tag.Previous }}[{{ .Tag.Name }}]{{ else }}{{ .Tag.Name }}{{ end }} - {{ datetime "2006-01-02" .Tag.Date }}
+{{ if .CommitGroups -}}
+{{ range .CommitGroups -}}
+{{ .Title }}:
+{{ range .Commits -}}
+{{- if .Subject -}}
+- {{ if .Scope }}**{{ .Scope }}:** {{ end }}{{ .Subject }}
+{{- end -}}
+{{ end }}
+{{ end -}}
+{{ else }}
+{{ range .Commits -}}
+{{- if .Subject -}}
+- {{ if .Scope }}**{{ .Scope }}:** {{ end }}{{ .Subject }}
+{{- end -}}
+{{ end }}
+{{ end -}}
+
+{{- if .NoteGroups -}}
+{{ range .NoteGroups -}}
+{{ .Title }}:
+{{ range .Notes }}
+{{ .Body }}
+{{ end }}
+{{ end -}}
+{{ end -}}
+{{ end -}}
+
+{{- if .Versions }}
+[Unreleased]: {{ .Info.RepositoryURL }}/compare/{{ $latest := index .Versions 0 }}{{ $latest.Tag.Name }}...HEAD
+{{ range .Versions -}}
+{{ if .Tag.Previous -}}
+[{{ .Tag.Name }}]: {{ $.Info.RepositoryURL }}/compare/{{ .Tag.Previous.Name }}...{{ .Tag.Name }}
+{{ end -}}
+{{ end -}}
+{{ end -}}