[meta] add auto-changelog

.npmrc

@@ -1 +1,3 @@
 package-lock=false
+allow-same-version=true
+message=v%s

package.json

@@ -14,7 +14,9 @@
 		"lint": "eslint .",
 		"preaudit": "npm install --package-lock --package-lock-only",
 		"audit": "npm audit",
-		"postaudit": "rm package-lock.json"
+		"postaudit": "rm package-lock.json",
+		"version": "auto-changelog && git add CHANGELOG.md",
+		"postversion": "auto-changelog && git add CHANGELOG.md && git commit --no-edit --amend && git tag -f \"v$(node -e \"console.log(require('./package.json').version)\")\""
 	},
 	"repository": {
 		"type": "git",
@@ -37,6 +39,7 @@
 	"dependencies": {},
 	"devDependencies": {
 		"@ljharb/eslint-config": "^13.1.1",
+		"auto-changelog": "^1.16.2",
 		"covert": "^1.1.1",
 		"eslint": "^5.12.1",
 		"tape": "^4.9.2"
@@ -62,5 +65,12 @@
 	},
 	"engines": {
 		"node": ">= 0.4"
+	},
+	"auto-changelog": {
+		"output": "CHANGELOG.md",
+		"template": "keepachangelog",
+		"unreleased": false,
+		"commitLimit": false,
+		"backfillLimit": false
 	}
 }