Update README.md prompt

Author: Doppp

README.md

@@ -24,18 +24,20 @@ than treating one umbrella survey as a substitute for studying the lab.
 The simplest learner experience uses **Codex in the ChatGPT desktop app**. Open
 Codex, start a local coding workspace, and paste this prompt:
 
-> Install and launch explorables from
-> https://github.com/Doppp/explorables.
->
-> Create a new `explorables` folder in my Documents folder. If that folder
-> already exists, do not overwrite it; ask me what to do. Clone the repository
-> using HTTPS, read its `AGENTS.md`, and follow its instructions. Check for
-> Node.js 24 and pnpm 11, but ask before installing or changing system
-> software. Install the locked dependencies with `pnpm install
-> --frozen-lockfile`, run `pnpm course`, and open the printed local course
-> library. Help me choose a course, then read that course's `AGENTS.md` and
-> follow its tutoring policy. Ask me to predict, let me attempt exercises, run
-> tests, and give the smallest useful hint before showing more.
+```bash
+Install and launch explorables from
+https://github.com/Doppp/explorables.
+
+Create a new `explorables` folder in my Documents folder. If that folder
+already exists, do not overwrite it; ask me what to do. Clone the repository
+using HTTPS, read its `AGENTS.md`, and follow its instructions. Check for
+Node.js 24 and pnpm 11, but ask before installing or changing system
+software. Install the locked dependencies with `pnpm install
+--frozen-lockfile`, run `pnpm course`, and open the printed local course
+library. Help me choose a course, then read that course's `AGENTS.md` and
+follow its tutoring policy. Ask me to predict, let me attempt exercises, run
+tests, and give the smallest useful hint before showing more.
+```
 
 Codex will ask for permission before running some commands or accessing a
 folder. Review and approve the actions needed to clone the public repository,