Fix highlighting and get tag pages

gatsby-node.js

@@ -19,7 +19,7 @@ exports.createPages = async ({ graphql, actions }) => {
 
     const result = await graphql(`
         query {
-            allMarkdownRemark {
+            postsRemark: allMarkdownRemark {
                 edges {
                     node {
                         fields {
@@ -28,10 +28,15 @@ exports.createPages = async ({ graphql, actions }) => {
                     }
                 }
             }
+            tagsGroup: allMarkdownRemark {
+                group(field: frontmatter___tags) {
+                    fieldValue
+                }
+            }
         }
     `);
 
-    result.data.allMarkdownRemark.edges.forEach(({ node }) => {
+    result.data.postsRemark.edges.forEach(({ node }) => {
         createPage({
             path: node.fields.slug,
             component: path.resolve(`./src/templates/post.js`),
@@ -40,4 +45,14 @@ exports.createPages = async ({ graphql, actions }) => {
             }
         });
     });
+
+    result.data.tagsGroup.group.forEach((tag) => {
+        createPage({
+            path: `/tags/${tag.fieldValue}/`,
+            component: path.resolve(`./src/templates/tag.js`),
+            context: {
+                tag: tag.fieldValue
+            }
+        });
+    });
 };