Add docs configuration

To allow rendering the track's documents on the v3 website, we're introducing a docs/config.json file.

This commit adds the docs/config.json file.

Author: ErikSchierboom

docs/config.json

@@ -0,0 +1,32 @@
+{
+  "docs": [
+    {
+      "uuid": "70e0f03a-58d9-4ef5-a541-8eeeef6fbbbf",
+      "slug": "installation",
+      "path": "docs/INSTALLATION.md",
+      "title": "Installing PHP locally",
+      "blurb": "Learn how to install PHP locally to solve Exercism's exercises on your own machine"
+    },
+    {
+      "uuid": "3fc49161-d224-4a1b-a741-894847232521",
+      "slug": "learning",
+      "path": "docs/LEARNING.md",
+      "title": "How to learn PHP",
+      "blurb": "An overview of how to get started from scratch with PHP"
+    },
+    {
+      "uuid": "2e799044-c3a1-40a8-833a-6407fe7ec7ce",
+      "slug": "tests",
+      "path": "docs/TESTS.md",
+      "title": "Testing on the PHP track",
+      "blurb": "Learn how to test your PHP exercises on Exercism"
+    },
+    {
+      "uuid": "6cd7aa02-1632-4ecc-b46d-163c41e47b35",
+      "slug": "resources",
+      "path": "docs/RESOURCES.md",
+      "title": "Useful PHP resources",
+      "blurb": "A collection of useful resources to help you master PHP"
+    }
+  ]
+}