Add Ko-fi button

Author: maoberlehner

README.md

@@ -7,6 +7,8 @@
 
 > Lazy hydration of server-side rendered Vue.js components.
 
+[![ko-fi](https://www.ko-fi.com/img/githubbutton_sm.svg)](https://ko-fi.com/O4O7U55Y)
+
 ## Motivation
 
 `vue-lazy-hydration` is a renderless Vue.js component to **improve Estimated Input Latency and Time to Interactive** of server-side rendered Vue.js applications. This can be achieved **by using lazy hydration to delay the hydration of pre-rendered HTML**.