chore: Add config files for git-chglog

.chglog/CHANGELOG.tpl.md

+{{ if .Versions -}}
+<a name="unreleased"></a>
+## [Unreleased]
+
+{{ if .Unreleased.CommitGroups -}}
+{{ range .Unreleased.CommitGroups -}}
+{{ .Title }}
+
+{{ range .Commits -}}
+  * {{if .Refs}}{{range .Refs}}#{{.Ref}} {{end}}{{end}}{{ 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 }}
+{{ range .CommitGroups -}}
+{{ .Title }}
+{{ range .Commits -}}
+  * {{ if .Scope }}**{{ .Scope }}:** {{ end }}{{ .Subject }}
+{{ 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 -}}
\ No newline at end of file

.chglog/config.yml

+style: gitlab
+template: CHANGELOG.tpl.md
+info:
+  title: CHANGELOG
+  repository_url: https://dev.gajim.org/gajim/python-nbxmpp
+options:
+  commits:
+    filters:
+      Type:
+        - feat
+        - perf
+        - fix
+  commit_groups:
+    sort_by: Custom
+    title_order:
+      - feat
+      - perf
+      - fix
+    title_maps:
+      feat: New
+      perf: Performance Improvements
+      fix: Bug Fixes
+  header:
+    pattern: "^(\\w*)\\:\\s(.*)$"
+    pattern_maps:
+      - Type
+      - Subject
+  issues:
+    prefix:
+      - "#"
+  refs:
+    actions:
+      - Fixes