Initial check-in of new React docs and website

Co-authored-by: Dan Abramov <dan.abramov@me.com>
Co-authored-by: Sylwia Vargas <sylwia.vargas@gmail.com>
Co-authored-by: Dan Lebowitz <dan.lebo@me.com>
Co-authored-by: Razvan Gradinar <grazvan@fb.com>
Co-authored-by: Jared Palmer <jared@palmer.net>
Co-authored-by: Dane Grant <danecando@gmail.com>
Co-authored-by: Dustin Goodman <dustin.s.goodman@gmail.com>
Co-authored-by: Rick Hanlon <rickhanlonii@gmail.com>
Co-authored-by: Maggie Appleton <maggie.fm.appleton@gmail.com>
Co-authored-by: Alex Moldovan <alex.n.moldovan@gmail.com>
Co-authored-by: Ives van Hoorne <ives.v.h@gmail.com>
Co-authored-by: Brian Vaughn <bvaughn@fb.com>

scripts/generateBlogIndex.js

@@ -0,0 +1,69 @@
+const fs = require('fs-extra');
+const path = require('path');
+const fm = require('gray-matter');
+const globby = require('globby');
+const parseISO = require('date-fns/parseISO');
+const readingTime = require('reading-time');
+const {markdownToHtml} = require('../plugins/markdownToHtml');
+
+/**
+ * This looks at the ./src/pages/blog directory and creates a route manifest that can be used
+ * in the sidebar and footers, and (in theory) category and author pages.
+ *
+ * For now, the blog manifest is a big array in reverse chronological order.
+ */
+Promise.resolve()
+  .then(async () => {
+    const routes = [];
+    const blogPosts = await globby('src/pages/blog/**/*.md');
+
+    for (let postpath of blogPosts) {
+      const [year, month, day, title] = postpath
+        .replace('src/pages/blog/', '')
+        .split('/');
+
+      const rawStr = await fs.readFile(postpath, 'utf8');
+      const {data, excerpt, content} = fm(rawStr, {
+        excerpt: function firstLine(file, options) {
+          file.excerpt = file.content.split('\n').slice(0, 2).join(' ');
+        },
+      });
+      const rendered = await markdownToHtml(excerpt.trimLeft().trim());
+
+      routes.unshift({
+        path: postpath.replace('src/pages', ''),
+        date: [year, month, day].join('-'),
+        title: data.title,
+        author: data.author,
+        excerpt: rendered,
+        readingTime: readingTime(content).text,
+      });
+    }
+
+    const sorted = routes.sort((post1, post2) =>
+      parseISO(post1.date) > parseISO(post2.date) ? -1 : 1
+    );
+    const blogManifest = {
+      routes: sorted,
+    };
+    const blogRecentSidebar = {
+      routes: [
+        {
+          title: 'Recent Posts',
+          path: '/blog',
+          heading: true,
+          routes: sorted.slice(0, 25),
+        },
+      ],
+    };
+
+    await fs.writeFile(
+      path.resolve('./src/blogIndex.json'),
+      JSON.stringify(blogManifest, null, 2)
+    );
+    await fs.writeFile(
+      path.resolve('./src/blogIndexRecent.json'),
+      JSON.stringify(blogRecentSidebar, null, 2)
+    );
+  })
+  .catch(console.error);