scripts: Add update_changelog.sh

It is of unknown quality and whether it actually works or not

scripts/update_changelog.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+if [[ $# -ne 3 ]]; then
+    echo "Usage $0 0 5 0"
+    exit 2
+fi
+
+LOG=$(cat CHANGELOG.md | tail -n +2)
+DATE=$(date +%F)
+
+PREVPATCH=$(($3-1))
+PREVMIN=$2
+if [[ $PREVPATCH -lt 0 ]]; then
+    PREVMIN=$(($2-1))
+    PREVPATCH="FIXME"
+    echo "Warning: Previous version needs to be manually modified in [Full Changelog]"
+fi
+N=$'\n'
+NEW="# Change Log${N}${N}## [v$1.$2.$3](https://github.com/ckb-next/ckb-next/tree/v$1.$2.$3) ($DATE)${N}[Full Changelog](https://github.com/ckb-next/ckb-next/compare/v$1.$PREVMIN.$PREVPATCH...v$1.$2.$3)${N}${N}Support for new devices:${N}- ${N}${N}Important bugfixes:${N}- ${N}${N}New features:${N}- ${N}${N}Notes for packagers:${N}- ${N}"
+echo "${NEW}${LOG}" > CHANGELOG.md