feat(guide): add footer link to article source on GitHub

fix/suggested-changes

client/gatsby-node.js

@@ -4,6 +4,7 @@ const { createFilePath } = require('gatsby-source-filesystem');
 
 const { dasherize } = require('./utils');
 const { blockNameify } = require('./utils/blockNameify');
+const { getGithubPath } = require('./utils/getGithubPath');
 const {
   createChallengePages,
   createBlockIntroPages,
@@ -33,10 +34,16 @@ exports.onCreateNode = function onCreateNode({ node, actions, getNode }) {
     const slug = createFilePath({ node, getNode });
     if (!slug.includes('LICENSE')) {
       const {
+        fileAbsolutePath,
         frontmatter: { component = '' }
       } = node;
       createNodeField({ node, name: 'slug', value: slug });
       createNodeField({ node, name: 'component', value: component });
+      createNodeField({
+        node,
+        name: 'githubPath',
+        value: getGithubPath(fileAbsolutePath)
+      });
     }
   }
 };
@@ -79,6 +86,7 @@ exports.createPages = function createPages({ graphql, actions }) {
                   slug
                   nodeIdentity
                   component
+                  githubPath
                 }
                 frontmatter {
                   block