docs: update Learning Hub for Copilot CLI v1.0.63–v1.0.64 changes (#2107)

- understanding-mcp-servers: add deferTools config option (v1.0.63),
  update /mcp install section to reflect new /mcp registry command (v1.0.64)
- agents-and-subagents: update rubber-duck agent section to reflect
  /subagents configuration and complementary model strategy (v1.0.64)
- creating-effective-skills: add argument-hint frontmatter field (v1.0.64)
- copilot-configuration-basics: add model family aliases (opus/sonnet/haiku/
  gpt/gemini) and /branch alias for /fork (v1.0.64)
- automating-with-hooks: add fix note for postToolUse pipe-separated
  matchers (v1.0.63)

Co-authored-by: github-actions[bot] <41898282+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: 2026-05-08
+lastUpdated: 2026-06-23
 estimatedReadingTime: '8 minutes'
 tags:
   - hooks
@@ -184,6 +184,8 @@ Hooks support two types: `"command"` for running local shell scripts, and `"http
 
 > **Important (v1.0.36+)**: Prior to v1.0.36, the `matcher` field was silently ignored — hooks with a `matcher` fired for all tool calls regardless of the regex. After upgrading to v1.0.36 or later, only tool calls whose name fully matches the `matcher` regex will trigger the hook. Review any existing `preToolUse`/`postToolUse` hooks that use `matcher` to ensure they still fire as expected.
 
+> **Fix (v1.0.63+)**: A bug caused `postToolUse` matchers using pipe-separated patterns (e.g., `"matcher": "Edit|Write"`) to be silently dropped, so hooks targeting multiple tools were incorrectly firing for all tool calls. This is fixed in v1.0.63 — `postToolUse` matchers now work correctly. If you rely on a formatter or linter that runs after specific tools, upgrade to v1.0.63 or later to ensure it fires only when intended.
+
 **cwd**: Working directory for the command (relative to repository root).
 
 **timeoutSec**: Maximum execution time in seconds (default: 30). The hook is killed if it exceeds this limit.