docs(readme): add deprecation notice

Bumps [postcss-preset-env](https://github.com/csstools/postcss-plugins/tree/HEAD/plugin-packs/postcss-preset-env) from 8.4.2 to 8.5.0.
- [Changelog](https://github.com/csstools/postcss-plugins/blob/main/plugin-packs/postcss-preset-env/CHANGELOG.md)
- [Commits](https://github.com/csstools/postcss-plugins/commits/HEAD/plugin-packs/postcss-preset-env)

---
updated-dependencies:
- dependency-name: postcss-preset-env
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

README.md

@@ -1,5 +1,9 @@
 <h1 align="center">x-markdown-css</h1>
 
+> [!IMPORTANT]  
+> I am working on a new CSS styling library, so `x-markdown-css` is deprecated.  
+> PS. Sass dev team supports Palestine Hamas. **I am dropping it.**
+
 <center>
 
 [![NPM Version](https://img.shields.io/npm/v/x-markdown-css)](https://www.npmjs.com/package/x-markdown-css)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "x-markdown-css",
-  "version": "0.1.5",
+  "version": "0.1.6",
   "description": "A simple and customizable markdown CSS stylesheet for everyone.",
   "keywords": [
     "markdown",
@@ -47,11 +47,11 @@
     "sass": "^1.58.3"
   },
   "devDependencies": {
-    "@kuohuanhuan/stylelint-config": "^0.0.4",
+    "@kuohuanhuan/stylelint-config": "^0.0.5",
     "@lodder/grunt-postcss": "^3.1.1",
     "autoprefixer": "^10.4.13",
     "bumpp": "^9.0.0",
-    "cssnano": "^5.1.15",
+    "cssnano": "^6.0.0",
     "grunt": "^1.6.1",
     "grunt-sass": "^3.1.0",
     "load-grunt-tasks": "^5.1.0",