docs: add support badges and clearer support options

Author: happysnaker

README.md

@@ -1,5 +1,8 @@
 # CSAPPLabsAndNotes
 
+[![Stars](https://img.shields.io/github/stars/happysnaker/CSAPPLabsAndNotes?style=social)](https://github.com/happysnaker/CSAPPLabsAndNotes/stargazers)
+[![Support](https://img.shields.io/badge/support-WeChat%20%26%20Alipay-7aa2ff)](https://happysnaker.github.io/support/)
+
 Notes, walkthroughs, and lab material collected while studying **Computer Systems: A Programmer's Perspective (CS:APP)**.
 
 ## Overview
@@ -46,3 +49,9 @@ If this repo helped you save time while learning systems fundamentals:
 - support my open-source work via the support page: [happysnaker.github.io/support](https://happysnaker.github.io/support/)
 - if these notes saved you time while preparing for systems interviews or labs, a small tip is appreciated
 - if you want lightweight async feedback on a public GitHub profile, README, or portfolio page, details are also available on the support page
+
+Typical support fit for this repo:
+
+- **¥9.9** — if one lab note or writeup saved you a debugging detour
+- **¥19.9** — if it helped your CS:APP study or systems interview prep materially
+- **¥99** — if you want compact async feedback on your GitHub profile / README / technical portfolio