ci: update changelog template (#154)

Author: julesbertrand

templates/CHANGELOG.md.j2

@@ -2,19 +2,23 @@
 {% if context.history.unreleased | length > 0 %}
 {# UNRELEASED #}
 ## Unreleased
-{% for type_, commits in context.history.unreleased | dictsort %}
+{% for type_, commits in context.history.unreleased | dictsort %}{% if type_ == "enh" %}
+### {{ "Enhancements" | capitalize }}
+{% else %}
 ### {{ type_ | capitalize }}
-{% for commit in commits %}{% if type_ != "unknown" %}
+{% endif %}{% for commit in commits %}{% if type_ != "unknown" %}
 * {{ commit.message.rstrip() }} ([`{{ commit.short_hash }}`]({{ commit.hexsha | commit_hash_url }}))
 {% else %}
 * {{ commit.message.rstrip() }} ([`{{ commit.short_hash }}`]({{ commit.hexsha | commit_hash_url }}))
 {% endif %}{% endfor %}{% endfor %}{% endif %}
 {% for version, release in context.history.released.items() %}
 {# RELEASED #}
 ## {{ version.as_tag() }} ({{ release.tagged_date.strftime("%Y-%m-%d") }})
-{% for type_, commits in release["elements"] | dictsort %}
+{% for type_, commits in release["elements"] | dictsort %}{% if type_ == "enh" %}
+### {{ "Enhancements" | capitalize }}
+{% else %}
 ### {{ type_ | capitalize }}
-{% for commit in commits %}{% if type_ != "unknown" %}
+{% endif %}{% for commit in commits %}{% if type_ != "unknown" %}
 * {{ commit.message.rstrip() }} ([`{{ commit.short_hash }}`]({{ commit.hexsha | commit_hash_url }}))
 {% else %}
 * {{ commit.message.rstrip() }} ([`{{ commit.short_hash }}`]({{ commit.hexsha | commit_hash_url }}))