Make commits conform to mkchlog format

This introduces mkchlog to the project so that the changelog could be
auto-generated.

changelog:
	section: dev
	inherit: title
	title-is-enough: true

.github/workflows/changelog.yml

@@ -0,0 +1,22 @@
+
+on:
+  push:
+    branches:
+      - master
+      - 'test-ci/**'
+  pull_request:
+
+name: Check changelog
+
+jobs:
+  changelog:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+        with:
+          # This is critically important!
+          # The action won't work without this
+          fetch-depth: 0
+      - name: Check commits
+        uses: Kixunil/mkchlog-action@master

.mkchlog.yml

@@ -0,0 +1,24 @@
+# mkchlog was introduced after this commit
+skip-commits-up-to: 2e06b367bcfcdff7f4ee280caf10a0f200348ee8
+
+
+sections:
+    security:
+        title: Security
+        description: This section contains very important security-related changes.
+        subsections:
+            vuln_fixes:
+                title: Fixed vulnerabilities
+    breaking:
+        title: Breaking changes
+    feat:
+        title: New features
+    bug:
+        title: Fixed bugs
+    perf:
+        title: Performance improvements
+    doc:
+        title: Documentation changes
+    dev:
+        title: Development
+        description: Internal development changes