docs: expand --resume session guidance in Chapter 02

Add detailed tips explaining how to find session IDs, how sessions
work across multiple terminals, and how to switch sessions from
inside an active session using /resume.

Remove redundant 'Switch Sessions While Working' section that is
now covered by the expanded tip.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: DanWahlin

02-context-conversations/README.md

@@ -307,6 +307,16 @@ copilot --resume
 copilot --resume abc123
 ```
 
+> 💡 **How do I find a session ID?** You don't need to memorize them. Running `copilot --resume` without an ID shows an interactive list of your previous sessions, their names, IDs, and when they were last active. Just pick the one you want.
+>
+> **What about multiple terminals?** Each terminal window is its own session with its own context. If you have Copilot CLI open in three terminals, that's three separate sessions. Running `--resume` from any terminal lets you browse all of them. The `--continue` flag grabs whichever session was closed most recently, no matter which terminal it was in.
+>
+> **Can I switch sessions without restarting?** Yes. Use the `/resume` slash command from inside an active session:
+> ```
+> > /resume
+> # Shows a list of sessions to switch to
+> ```
+
 ### Organize Your Sessions
 
 Give sessions meaningful names so you can find them later:
@@ -430,17 +440,6 @@ copilot
 > Find all TODO comments in @samples/book-app-project/**/*.py
 ```
 
-### Switch Sessions While Working
-
-Inside an interactive session, use the `/resume` command:
-
-```bash
-copilot
-
-> /resume
-# Shows a list of sessions to switch to
-```
-
 ### View Session Info
 
 ```bash