feat: Add redirects for all mdx pages that specify redirects

gatsby-node.js

@@ -1,7 +1,7 @@
 const path = require(`path`);
 
 exports.createPages = async ({ actions, graphql, reporter }) => {
-  const { createPage } = actions;
+  const { createPage, createRedirect } = actions;
 
   const result = await graphql(`
     {
@@ -11,6 +11,7 @@ exports.createPages = async ({ actions, graphql, reporter }) => {
             frontmatter {
               path
               template
+              redirects
             }
           }
         }
@@ -25,9 +26,22 @@ exports.createPages = async ({ actions, graphql, reporter }) => {
   }
 
   result.data.allMdx.edges.forEach(({ node }) => {
+    const { frontmatter } = node;
+
+    if (frontmatter.redirects) {
+      frontmatter.redirects.forEach((fromPath) => {
+        createRedirect({
+          fromPath,
+          toPath: frontmatter.path,
+          isPermanent: true,
+          redirectInBrowser: true,
+        });
+      });
+    }
+
     createPage({
-      path: node.frontmatter.path,
-      component: path.resolve(`src/templates/${node.frontmatter.template}.js`),
+      path: frontmatter.path,
+      component: path.resolve(`src/templates/${frontmatter.template}.js`),
       context: {}, // additional data can be passed via context
     });
   });