feat: add skills.json generation for MCP consumption

Add a bash script that generates dist/skills.json from all SKILL.md files
across plugins. The MCP server fetches this at runtime to serve skills
via its tool and resource APIs.

CI workflow updated to regenerate on every push to main when plugins change.

Ref: PF-4034

Author: jpuzz0

.github/workflows/update-plugins-md.yml

@@ -1,4 +1,4 @@
-name: Update PLUGINS.md
+name: Update generated files
 
 on:
   workflow_dispatch:
@@ -19,11 +19,12 @@ jobs:
       - run: git remote set-url origin git@github.com:patternfly/ai-helpers.git
       - run: |
           bash scripts/generate-plugins-md.sh
-          git diff --quiet PLUGINS.md README.md || {
+          bash scripts/generate-skills-json.sh
+          git diff --quiet PLUGINS.md README.md dist/skills.json || {
             git config user.name "github-actions[bot]"
             git config user.email "github-actions[bot]@users.noreply.github.com"
-            git add PLUGINS.md README.md
-            git commit -m "docs: auto-update PLUGINS.md and README plugin table"
+            git add PLUGINS.md README.md dist/skills.json
+            git commit -m "docs: auto-update PLUGINS.md, README plugin table, and skills index"
             git pull --rebase
             git push
           }