site: add Dwolla blog post, add support for canonical URLs (#2357)

* Add blog post about implementing the CMS with Jekyll, add support for canonical URLs

* fix formatting

* add cross post link

website/src/css/imports/docs.css

@@ -182,6 +182,18 @@
     }
   }
 
+  figure {
+    margin-left: 0;
+
+    .gatsby-highlight {
+      margin-top: -20px;
+    }
+  }
+
+  figcaption {
+    font-style: italic;
+  }
+
   :not(pre) > code {
     color: inherit;
     background: $lightestGrey;

website/src/templates/blog-post.js

@@ -24,7 +24,15 @@ export const BlogPostTemplate = ({ title, author, date, body, html }) => (
 
 const BlogPost = ({ data }) => {
   const { html, frontmatter } = data.markdownRemark;
-  const { author, title, date, description, meta_description, twitter_image } = frontmatter;
+  const {
+    author,
+    title,
+    date,
+    description,
+    meta_description,
+    twitter_image,
+    canonical_url,
+  } = frontmatter;
   const { siteUrl } = data.site.siteMetadata;
   const twitterImageUrl =
     twitter_image && `${trimEnd(siteUrl, '/')}/${trimStart(twitter_image, '/')}`;
@@ -36,6 +44,7 @@ const BlogPost = ({ data }) => {
       <Helmet>
         <title>{title}</title>
         {desc && <meta name="description" content={desc} />}
+        {canonical_url && <link rel="canonical" href={canonical_url} />}
       </Helmet>
       <TwitterMeta title={title} description={desc} image={twitterImageUrl} />
       <BlogPostTemplate title={title} author={author} date={date} html={html} />
@@ -60,6 +69,7 @@ export const pageQuery = graphql`
         date(formatString: "MMMM D, YYYY")
         author
         twitter_image
+        canonical_url
       }
       html
     }