CHANGES.md: Use towncrier to manage the change log

vector-im/element-ios#4393

More info in [CONTRIBUTING](CONTRIBUTING.md#changelog)

.github/PULL_REQUEST_TEMPLATE.md

@@ -3,6 +3,6 @@
 * [ ] I read the [contributing guide](https://github.com/vector-im/element-ios/blob/develop/CONTRIBUTING.md)
 * [ ] UI change has been tested on both light and dark themes, in portrait and landscape orientations and on iPhone and iPad simulators
 * [ ] Pull request is based on the develop branch
-* [ ] Pull request updates [CHANGES.rst](https://github.com/vector-im/riot-ios/blob/develop/CHANGES.rst)
+* [ ] Pull request contains a changelog file in ./changelog.d. See <https://github.com/matrix-org/matrix-ios-sdk/blob/develop/CONTRIBUTING.md#changelog>
 * [ ] Pull request includes screenshots or videos of UI changes
-* [ ] Pull request includes a [sign off](https://github.com/matrix-org/synapse/blob/master/CONTRIBUTING.md#sign-off)
+* [ ] Pull request includes a [sign off](https://github.com/matrix-org/matrix-ios-sdk/blob/develop/CONTRIBUTING.md#sign-off)

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contributing code to Matrix
 
-Please read Synapse [contributing guide](https://github.com/matrix-org/synapse/blob/master/CONTRIBUTING.md).
+Please read the matrix-ios-sdk [contributing guide](https://github.com/matrix-org/matrix-ios-sdk/blob/develop/CONTRIBUTING.md).
 
 # Contributing code to Element iOS
 

changelog.d/.gitignore

@@ -0,0 +1 @@
+!.gitignore

changelog.d/4393.build

@@ -0,0 +1 @@
+CHANGES.md: Use towncrier to manage the change log. More info in [CONTRIBUTING](CONTRIBUTING.md#changelog).

changelog.d/_template.md.jinja

@@ -0,0 +1,52 @@
+{# iOS Repositories #}
+{%- set gh_sdk = "https://github.com/matrix-org/matrix-ios-sdk" -%}
+{%- set gh_kit = "https://github.com/matrix-org/matrix-ios-kit" -%}
+{%- set gh_element = "https://github.com/vector-im/element-ios" -%}
+
+## {{ versiondata.name }} {{ versiondata.version }} ({{ versiondata.date }})
+{% for section, _ in sections.items() %}
+
+{% if sections[section] %}
+{% for category, val in definitions.items() if category in sections[section]%}
+{{ definitions[category]['name'] }}
+
+{% if definitions[category]['showcontent'] %}
+{% for text, values in sections[section][category].items() %}
+{# Build all types of links we can have from our different repositories #}
+{%- set links = [] -%}
+{%- for value in values %}
+    {%- if value.startswith("sdk-") %}
+        {%- set gh_issue = value.replace("sdk-", "") -%}
+        {{- links.append( "[#%s](%s/issues/%s)" | format(gh_issue, gh_sdk, gh_issue) ) | default("", True) -}}
+    {%- elif value.startswith("kit-") %}
+        {%- set gh_issue = value.replace("kit-", "") -%}
+        {{- links.append( "[#%s](%s/issues/%s)" | format(gh_issue, gh_kit, gh_issue) ) | default("", True) -}}
+    {%- elif value.startswith("#") %}
+        {%- set gh_issue = value.replace("#", "") -%}
+        {{- links.append( "[#%s](%s/issues/%s)" | format(gh_issue, gh_element, gh_issue) ) | default("", True) -}}
+    {%- elif value.startswith("pr-") %}
+        {%- set pr = value.replace("pr-", "#") -%}
+        {{- links.append(pr) | default("", True) -}}
+    {% else %}
+        {{- links.append(value) | default("", True) -}}
+    {% endif -%}
+{% endfor -%}
+- {{ text }} ({{ links | join(', ') }})
+{% endfor %}
+{% else %}
+- {{ sections[section][category]['']|join(', ') }}
+
+{% endif %}
+{% if sections[section][category]|length == 0 %}
+No significant changes.
+
+{% else %}
+{% endif %}
+
+{% endfor %}
+{% else %}
+No significant changes.
+
+
+{% endif %}
+{% endfor %}

towncrier.toml

@@ -0,0 +1,45 @@
+[tool.towncrier]
+name = "Changes in"
+filename = "CHANGES.md"
+directory = "changelog.d"
+template = "changelog.d/_template.md.jinja"
+
+[[tool.towncrier.type]]
+    directory = "feature"
+    name = "✨ Features"
+    showcontent = true
+
+[[tool.towncrier.type]]
+    directory = "change"
+    name = "🙌 Improvements"
+    showcontent = true
+
+[[tool.towncrier.type]]
+    directory = "bugfix"
+    name = "🐛 Bugfixes"
+    showcontent = true
+
+[[tool.towncrier.type]]
+    directory = "api"
+    name = "⚠️ API Changes"
+    showcontent = true
+
+[[tool.towncrier.type]]
+    directory = "i18n"
+    name = "🗣 Translations"
+    showcontent = true
+
+[[tool.towncrier.type]]
+    directory = "build"
+    name = "🧱 Build"
+    showcontent = true
+
+[[tool.towncrier.type]]
+    directory = "doc"
+    name = "📄 Documentation"
+    showcontent = true
+
+[[tool.towncrier.type]]
+    directory = "misc"
+    name = "Others"
+    showcontent = true