Implementation of the project selector

package.json

@@ -94,8 +94,31 @@
       }]
     },
     "configuration": {
+      "$id": "#gobalconfiguration",
       "title": "Front Matter: use frontmatter.json for shared team settings",
+      "type": "object",
       "properties": {
+        "frontMatter.projects": {
+          "type": "array",
+          "markdownDescription": "Specify the list of projects to load in the Front Matter CMS. [Check in the docs](https://frontmatter.codes/docs/settings/overview#frontmatter.projects)",
+          "default": [],
+          "items": {
+            "type": "object",
+            "properties": {
+              "name": {
+                "type": "string",
+                "markdownDescription": "Specify the name of the project."
+              },
+              "default": {
+                "type": "boolean",
+                "markdownDescription": "Specify if this project is the default project to load."
+              },
+              "configuration": {
+                "$ref": "#gobalconfiguration"
+              }
+            }
+          }
+        },
         "frontMatter.sponsors.ai.enabled": {
           "type": "boolean",
           "default": false,