build: add templates for changelog and release notes

templates/.macros.j2

@@ -0,0 +1,23 @@
+{% macro render_single_commit(commit) -%}
+* {% if commit["scope"] is not none %}**{{ commit["scope"] }}** {% endif %}{{ commit["descriptions"][0].rstrip() }} ([`{{commit.short_hash }}`]({{ commit.hexsha | commit_hash_url }}))
+{% for line in commit["descriptions"][1:] %}
+{{ line | indent(2, first=True, blank=True) -}}
+{% endfor %}
+{%- endmacro %}
+
+{% macro render_unknown_commit(commit) -%}
+* {{ commit.message.rstrip().split("\n")[0] }} ([`{{ commit.short_hash }}`]({{ commit.hexsha | commit_hash_url }}))
+{% for line in commit.message.rstrip().split("\n")[1:] %}
+{{ line | indent(2, first=True, blank=True) -}}
+{% endfor %}
+{%- endmacro %}
+
+{%- macro render_elements(elements) -%}
+{% for type_, commits in elements | dictsort %}
+### {{ type_ | capitalize }}
+{% for commit in commits -%}{% if type_ != "unknown" %}
+{{ render_single_commit(commit).rstrip() }}
+{% else %}
+{{ render_unknown_commit(commit).rstrip() }}
+{% endif %}{%- endfor %}{% endfor %}
+{%- endmacro -%}

templates/.release_notes.md.j2

@@ -0,0 +1,3 @@
+{% import ".macros.j2" as macros -%}
+# {{ version.as_tag() }} ({{ release.tagged_date.strftime("%Y-%m-%d") }})
+{{ macros.render_elements(release["elements"]) }}

templates/CHANGELOG.md.j2

@@ -0,0 +1,12 @@
+# CHANGELOG
+{% import ".macros.j2" as macros -%}
+{% if context.history.unreleased | length > 0 %}
+{# UNRELEASED #}
+## Unreleased
+{{ macros.render_elements(context.history.unreleased) -}}
+{% endif %}
+{% for version, release in context.history.released.items() %}
+{# RELEASED #}
+## {{ version.as_semver_tag() }} ({{ release.tagged_date.strftime("%Y-%m-%d") }})
+{{ macros.render_elements(release["elements"]) -}}
+{% endfor %}