Add noob-mode skill and plugin (#857)

Noob Mode is a plain-English translation layer for non-technical Copilot
CLI users (PMs, business stakeholders, designers, and anyone new to the
command line). When activated, it translates every approval prompt, error
message, and technical output into clear, jargon-free English with
color-coded risk indicators.

Includes:
- Standalone skill (skills/noob-mode/) with SKILL.md and bundled
  glossary (100+ terms) and before/after examples
- Plugin (plugins/noob-mode/) for installation via
  copilot plugin install noob-mode@awesome-copilot

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

plugins/noob-mode/.github/plugin/plugin.json

@@ -0,0 +1,22 @@
+{
+  "name": "noob-mode",
+  "description": "Plain-English translation layer for non-technical Copilot CLI users. Translates every approval prompt, error message, and technical output into clear, jargon-free English with color-coded risk indicators.",
+  "version": "1.0.0",
+  "author": {
+    "name": "Awesome Copilot Community"
+  },
+  "repository": "https://github.com/github/awesome-copilot",
+  "license": "MIT",
+  "keywords": [
+    "accessibility",
+    "plain-english",
+    "non-technical",
+    "beginner",
+    "translation",
+    "copilot-cli",
+    "ux"
+  ],
+  "skills": [
+    "./skills/noob-mode/"
+  ]
+}