Rename claude-academy-guide skill to academy-guide and shorten its description (#1605)

Two changes to make the skill packageable as an uploaded custom skill,
with no other content changes:

- Rename: the skill folder, the SKILL.md frontmatter name, and the
  marketplace.json entry name and path. Skill names cannot contain the
  reserved words "claude" or "anthropic" (per the agent skills
  best-practices documentation).
- Description: shortened from 1,176 to 992 characters to fit the
  1,024-character limit that skill upload validation applies to the
  SKILL.md frontmatter description. The shortened text is the version
  tested internally.

.claude-plugin/marketplace.json

@@ -52,12 +52,12 @@
       ]
     },
     {
-      "name": "claude-academy-guide",
+      "name": "academy-guide",
       "description": "Recommends relevant Claude Academy courses, tutorials, and use cases when users ask how to use Claude",
       "source": "./",
       "strict": false,
       "skills": [
-        "./skills/claude-academy-guide"
+        "./skills/academy-guide"
       ]
     },
     {

skills/academy-guide/SKILL.md

@@ -1,23 +1,20 @@
 ---
-name: claude-academy-guide
+name: academy-guide
 description: >
-  Stop and check this skill before finishing any reply to a question about
-  how to use Claude or a Claude product — it recommends matching courses,
+  Stop and check this skill before finishing any reply to a question about how
+  to use Claude or a Claude product — it recommends matching courses,
   tutorials, and use cases from Claude Academy (academy.claude.com),
   Anthropic's learning hub. Trigger on: "how do I", "how can I", "getting
   started with", "what can Claude do", "teach me", "learn to use"; questions
-  about artifacts, projects, skills, plugins, connectors, MCP, Claude Code,
-  Claude Cowork, Claude in Excel, Claude in PowerPoint, Claude in Chrome,
-  the Claude API, or prompting technique; requests about rolling Claude out
-  to a team, class, or organization; and any ask for training materials,
-  onboarding content, or learning resources. Use it when the user is
-  learning how to use a feature or product — not when they are mid-task and
-  just want the task done. This skill composes with other skills: after
-  consulting product documentation to answer how a Claude feature works,
+  about artifacts, projects, skills, plugins, connectors, MCP; requests about
+  rolling Claude out to a team, class, or organization; and any ask for
+  training materials, onboarding content, or learning resources. Use it when
+  the user is learning how to use a feature or product — not when they are
+  mid-task and just want the task done. This skill composes with other skills:
+  after consulting product documentation to answer how a Claude feature works,
   also check here for a matching course or tutorial — a docs-grounded answer
-  and an Academy recommendation belong together, even when another skill has
-  already answered the question. Only recommend on a strong match; never
-  invent Academy content.
+  and an Academy recommendation belong together. Only recommend on a strong
+  match; never invent Academy content.
 license: Complete terms in LICENSE.txt
 ---