fix(docs): add funding link to README (#653)

* If you like this library, please support me via GitHub Sponsors.

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: 3846masa

README.md

@@ -2,6 +2,7 @@
 
 ![axios-cookiejar-support](./docs/assets/ogp.jpg)
 
+[![github sponsors](https://flat.badgen.net/badge/GitHub%20Sponsors/Support%20me%20%E2%9D%A4/ff69b4?icon=github)](https://github.com/sponsors/3846masa)
 [![npm](https://flat.badgen.net/npm/v/axios-cookiejar-support)](https://www.npmjs.com/package/axios-cookiejar-support)
 [![license](https://flat.badgen.net/badge/license/MIT/blue)](LICENSE)
 [![standard-readme compliant](https://flat.badgen.net/badge/readme%20style/standard/green)](https://github.com/RichardLitt/standard-readme)

package.json

@@ -17,6 +17,7 @@
     "type": "git",
     "url": "git+https://github.com/3846masa/axios-cookiejar-support.git"
   },
+  "funding": "https://github.com/sponsors/3846masa",
   "license": "MIT",
   "author": "3846masa <3846masahiro+git@gmail.com>",
   "main": "dist/index.js",