docs: update Learning Hub for CLI v1.0.6–v1.0.10 changes (#1119)

- automating-with-hooks: add subagentStart event to hook events table,
  add cross-platform PascalCase event name compatibility note, add
  subagentStart example, expand hook config file location FAQ to include
  settings.json and config.json locations
- defining-custom-instructions: document that applyTo accepts both
  string and array formats (added in v1.0.6)
- installing-and-using-plugins: document --plugin-dir flag and the
  External Plugins section in /plugin list (added in v1.0.10)

Source: github/copilot-cli releases v1.0.6 through v1.0.10
(March 16–20, 2026)

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

website/src/content/docs/learning-hub/automating-with-hooks.md

@@ -3,7 +3,7 @@ title: 'Automating with Hooks'
 description: 'Learn how to use hooks to automate lifecycle events like formatting, linting, and governance checks during Copilot agent sessions.'
 authors:
   - GitHub Copilot Learning Hub Team
-lastUpdated: 2026-02-26
+lastUpdated: 2026-03-22
 estimatedReadingTime: '8 minutes'
 tags:
   - hooks
@@ -93,11 +93,16 @@ Hooks can trigger on several lifecycle events:
 | `preToolUse` | Before the agent uses any tool (e.g., `bash`, `edit`) | **Approve or deny** tool executions, block dangerous commands, enforce security policies |
 | `postToolUse` | After a tool completes execution | Log results, track usage, format code after edits, send failure alerts |
 | `agentStop` | Main agent finishes responding to a prompt | Run final linters/formatters, validate complete changes |
+| `subagentStart` | A subagent is spawned by the main agent | Inject additional context into the subagent's prompt, log subagent launches |
 | `subagentStop` | A subagent completes before returning results | Audit subagent outputs, log subagent activity |
 | `errorOccurred` | An error occurs during agent execution | Log errors for debugging, send notifications, track error patterns |
 
 > **Key insight**: The `preToolUse` hook is the most powerful — it can **approve or deny** individual tool executions. This enables fine-grained security policies like blocking specific shell commands or requiring approval for sensitive file operations.
 
+### Cross-Platform Event Name Compatibility
+
+Hook event names can be written in **camelCase** (e.g., `preToolUse`) or **PascalCase** (e.g., `PreToolUse`). Both are accepted, making hook configuration files compatible across GitHub Copilot CLI, VS Code, and Claude Code without modification. Hooks also support Claude Code's nested `matcher`/`hooks` structure alongside the standard flat format.
+
 ### Event Configuration
 
 Each hook entry supports these fields:
@@ -281,6 +286,28 @@ Send a Slack or Teams notification when an agent session completes:
 }
 ```
 
+### Injecting Context into Subagents
+
+The `subagentStart` hook fires when the main agent spawns a subagent (e.g., via the `task` tool). Use it to inject additional context—such as project conventions or security guidelines—directly into the subagent's prompt:
+
+```json
+{
+  "version": 1,
+  "hooks": {
+    "subagentStart": [
+      {
+        "type": "command",
+        "bash": "echo 'Follow the team coding standards in .github/instructions/ for all code changes.'",
+        "cwd": ".",
+        "timeoutSec": 5
+      }
+    ]
+  }
+}
+```
+
+This is especially useful in multi-agent workflows where subagents may not automatically inherit context from the parent session.
+
 ## Writing Hook Scripts
 
 For complex logic, use bundled scripts instead of inline bash commands:
@@ -327,7 +354,13 @@ echo "Pre-commit checks passed ✅"
 
 **Q: Where do I put hooks configuration files?**
 
-A: Place them in the `.github/hooks/` directory in your repository (e.g., `.github/hooks/my-hook.json`). You can have multiple hook files — all are loaded automatically. This makes hooks available to all team members.
+A: There are several supported locations, loaded in order of precedence:
+
+- **Repository-level** (shared with team): `.github/hooks/*.json` in your repository — all JSON files in this folder are loaded automatically
+- **Global settings**: `settings.json` or `settings.local.json` (user-level CLI config)
+- **Legacy config**: `config.json` (also supported)
+
+For team-wide hooks that everyone should use, `.github/hooks/` is the recommended location as it is version-controlled and shared automatically.
 
 **Q: Can hooks access the user's prompt text?**
 

website/src/content/docs/learning-hub/defining-custom-instructions.md

@@ -3,7 +3,7 @@ title: 'Defining Custom Instructions'
 description: 'Learn how to create persistent, context-aware instructions that guide GitHub Copilot automatically across your codebase.'
 authors:
   - GitHub Copilot Learning Hub Team
-lastUpdated: 2025-12-02
+lastUpdated: 2026-03-22
 estimatedReadingTime: '8 minutes'
 tags:
   - instructions
@@ -100,7 +100,17 @@ export function UserProfile({ userId, onUpdate }: UserProfileProps) {
 
 ## Scoping Instructions Effectively
 
-The `applyTo` field determines which files receive the instruction's guidance.
+The `applyTo` field determines which files receive the instruction's guidance. It accepts either a **comma-separated string** or an **array of glob patterns** — both formats work:
+
+```yaml
+# String format (comma-separated)
+applyTo: '**/*.ts, **/*.tsx'
+
+# Array format
+applyTo:
+  - '**/*.ts'
+  - '**/*.tsx'
+```
 
 ### Common Scoping Patterns
 

website/src/content/docs/learning-hub/installing-and-using-plugins.md

@@ -3,7 +3,7 @@ title: 'Installing and Using Plugins'
 description: 'Learn how to find, install, and manage plugins that extend GitHub Copilot CLI with reusable agents, skills, hooks, and integrations.'
 authors:
   - GitHub Copilot Learning Hub Team
-lastUpdated: 2026-02-26
+lastUpdated: 2026-03-22
 estimatedReadingTime: '8 minutes'
 tags:
   - plugins
@@ -177,6 +177,16 @@ copilot plugin update my-plugin
 copilot plugin uninstall my-plugin
 ```
 
+### Loading Plugins from a Local Directory
+
+You can load plugins directly from a local directory without installing them from a marketplace, using the `--plugin-dir` flag when starting Copilot:
+
+```bash
+copilot --plugin-dir /path/to/my-plugin
+```
+
+Plugins loaded this way appear in `/plugin list` under a separate **External Plugins** section, clearly distinguished from marketplace-installed plugins. This is useful for testing local plugins in development or loading private plugins that aren't published to any marketplace.
+
 ### Where Plugins Are Stored
 
 - **Marketplace plugins**: `~/.copilot/installed-plugins/MARKETPLACE/PLUGIN-NAME/`