Add new tool to bump version.

tools/bump-version.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+#
+# Bump latest version to file `_data/meta.yml`
+#
+# v2.5.1
+# https://github.com/cotes2020/jekyll-theme-chirpy
+# © 2020 Cotes Chung
+# Published under MIT License
+
+set -eu
+
+META_FILE="_data/meta.yml"
+
+_latest_tag="$(git describe --abbrev=0)"
+
+_version_field="version: $_latest_tag"
+
+if [[ ! -f $META_FILE ]]; then
+  echo "name: Chirpy" > $META_FILE
+  echo "$_version_field" >> $META_FILE
+else
+  sed -i "s/^version:.*/$_version_field/g" $META_FILE
+fi
+
+if [[ -n $(git status $META_FILE -s) ]]; then
+  git add $META_FILE
+  git commit -m "Bump version to $_latest_tag"
+fi