perf: Reduce initial bundle size / async bundle loading (#1456)

* feat: Move to React.lazy

* perf: Remove duplicate babel/runtime

* fix: Run yarn-deduplicate

* Further attempts to remove rich-markdown-editor from initial chunk

* perf: Lazy loading of authenticated routes

* perf: Move color picker to async loading
fix: Display placeholder when loading rich editor

* fix: Cache bust on auto reload

server/utils/parseDocumentIds.test.js

@@ -0,0 +1,38 @@
+/* eslint-disable flowtype/require-valid-file-annotation */
+import parseDocumentIds from "./parseDocumentIds";
+
+it("should not return non links", () => {
+  expect(parseDocumentIds(`# Header`).length).toBe(0);
+});
+
+it("should return an array of document ids", () => {
+  const result = parseDocumentIds(`# Header
+  
+  [internal](/doc/test-456733)
+  `);
+
+  expect(result.length).toBe(1);
+  expect(result[0]).toBe("test-456733");
+});
+
+it("should not return duplicate document ids", () => {
+  expect(parseDocumentIds(`# Header`).length).toBe(0);
+
+  const result = parseDocumentIds(`# Header
+  
+  [internal](/doc/test-456733)
+
+  [another link to the same doc](/doc/test-456733)
+  `);
+
+  expect(result.length).toBe(1);
+  expect(result[0]).toBe("test-456733");
+});
+
+it("should not return non document links", () => {
+  expect(parseDocumentIds(`[google](http://www.google.com)`).length).toBe(0);
+});
+
+it("should not return non document relative links", () => {
+  expect(parseDocumentIds(`[relative](/developers)`).length).toBe(0);
+});