docs: update course for Copilot CLI v1.0.22-v1.0.28 features

- Ch01: update 'steer' to 'remote control' to match renamed terminology (v1.0.26)
- Ch02: add tip about /add-dir accepting relative paths like ./src (v1.0.25)
- Ch04: add 'skills' field to agent frontmatter reference table (v1.0.22)
- Ch04: add explainer showing how agents and skills combine via skills field

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

Author: DanWahlin

01-setup-and-first-steps/README.md

@@ -569,7 +569,7 @@ Start a remote session with the `--remote` flag:
 copilot --remote
 ```
 
-Copilot CLI will display a link and provide access to a QR code. Open the link on your phone or in a desktop browser tab to watch the session in real time, send follow-up prompts, review plans, and steer the agent remotely. Sessions are user-specific so you can only access your own Copilot CLI sessions.
+Copilot CLI will display a link and provide access to a QR code. Open the link on your phone or in a desktop browser tab to watch the session in real time, send follow-up prompts, review plans, and remotely control the agent. Sessions are user-specific so you can only access your own Copilot CLI sessions.
 
 You can also enable remote access from inside an active session at any time:
 

02-context-conversations/README.md

@@ -843,6 +843,8 @@ copilot --add-dir /path/to/directory
 > /add-dir /path/to/directory
 ```
 
+> 💡 **Relative paths work too**: You can use relative paths like `./src` or `../sibling-folder` — the CLI resolves them to absolute paths automatically. This is handy when you're already in the right parent directory.
+
 **Context fills up too quickly**:
 - Be more specific with file references
 - Use `/clear` between different topics

04-agents-custom-instructions/README.md

@@ -131,7 +131,7 @@ When reviewing code, always check for:
 - Hardcoded secrets
 ```
 
-> 💡 **Required vs Optional**: The `description` field is required. Other fields like `name`, `tools`, and `model` are optional.
+> 💡 **Required vs Optional**: The `description` field is required. Other fields like `name`, `tools`, `skills`, and `model` are optional.
 
 ## Where to put agent files
 
@@ -508,6 +508,7 @@ You are a Python specialist focused on code quality and best practices.
 | `description` | **Yes** | What the agent does - helps Copilot understand when to suggest it |
 | `tools` | No | List of allowed tools (omit = all tools available). See tool aliases below. |
 | `target` | No | Limit to `vscode` or `github-copilot` only |
+| `skills` | No | List of skill names to load into agent context automatically at startup |
 
 ### Tool Aliases
 
@@ -522,6 +523,8 @@ Use these names in the `tools` list:
 >
 > ⚠️ **VS Code Only**: The `model` property (for selecting AI models) works in VS Code but is not supported in GitHub Copilot CLI. You can safely include it for cross-platform agent files. GitHub Copilot CLI will ignore it.
 
+> 💡 **Combining agents and skills**: The `skills` field lets an agent pre-load specific skills into its context at startup. For example, if your agent always needs the `code-checklist` skill, add `skills: [code-checklist]` to its frontmatter so it's automatically available without needing to invoke it separately. You'll learn more about creating skills in [Chapter 05](../05-skills/README.md).
+
 ### More Agent Templates
 
 > 💡 **Note for beginners**: The examples below are templates. **Replace the specific technologies with whatever your project uses.** The important thing is the *structure* of the agent, not the specific technologies mentioned.