Fix context7.json schema error, validate it in CI

.github/workflows/context7-validate.yml

@@ -0,0 +1,25 @@
+name: "✅ - Validate context7.json"
+
+on:
+  push:
+    paths:
+      - context7.json
+      - .github/workflows/context7-validate.yml
+  pull_request:
+    paths:
+      - context7.json
+      - .github/workflows/context7-validate.yml
+
+jobs:
+  validate:
+    name: "✅ - Check context7.json against the Context7 schema"
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      # Context7 gives no feedback on an invalid file. After #104 shipped a
+      # description over the 200-character limit, the library kept its
+      # default settings, so catch schema errors here instead.
+      - name: "✅ - Validate"
+        run: pipx run check-jsonschema==0.38.2 --schemafile https://context7.com/schema/context7.json context7.json

context7.json

@@ -3,7 +3,7 @@
   "url": "https://context7.com/mage-os/devdocs",
   "public_key": "pk_HsBSv7f4tLBOYsckJH4BP",
   "projectTitle": "Mage-OS",
-  "description": "Developer documentation for Mage-OS, a community-governed independent distribution of Magento Open Source, compatible with Magento 2 extensions and themes. Covers installation, module development, theming, APIs, testing, and XML configuration file references. Mage-OS 3.x also ships features Magento Open Source lacks, such as built-in Returns Management (RMA).",
+  "description": "Developer docs for Mage-OS, a community-driven distribution of Magento Open Source compatible with Magento 2 extensions: install, modules, themes, APIs, XML config and built-in RMA.",
   "excludeFiles": [
     "README.md",
     "CODEOWNERS",