Refine CI/CD pipeline

Make use of GitLab features like the package registry to store dist
packages, GitLab releases and broadcast the release to different
channels.

Overall, this enables developers to be push out releases for frequently
since the amount of manual work is reduced.

scripts/ci/create-release-message.sh

@@ -0,0 +1,28 @@
+#!/bin/sh
+
+VERSION="$1"
+
+section_active=""
+changelog_excerpt=""
+
+while IFS= read -r line; do
+    if [ "$section_active" ]; then
+        if [[ "$(echo "$line" | grep '^#')" ]]; then
+            section_active=""
+        else
+            changelog_excerpt="$(printf "%s\n%s" "$changelog_excerpt" "$line")"
+        fi
+    else
+        if [ "$line" = "## $VERSION" ]; then
+            section_active="1"
+        fi
+    fi
+done
+
+if [ "$changelog_excerpt" ]; then
+    printf "%s" "$changelog_excerpt"
+    exit 0
+else
+    echo "Could not find version in changelog: $VERSION"
+    exit 1
+fi