update build process

.babelrc

@@ -1,11 +1,30 @@
 {
   "sourceMaps": true,
   "presets": [
-    ["es2015", { "loose":true }],
-    "stage-0"
+    ["@babel/preset-env", {
+      "loose":true,
+      "targets": "> 1%, not dead",
+      "useBuiltIns": false,
+      "exclude": [
+        "transform-regenerator"
+      ]
+    }]
   ],
   "plugins": [
-    ["transform-decorators-legacy"],
-    ["transform-react-jsx", { "pragma": "h" }]
+    "@babel/plugin-syntax-dynamic-import",
+    [
+      "babel-plugin-transform-async-to-promises",
+      { "inlineHelpers": true, "externalHelpers": false }
+    ],
+    ["@babel/plugin-proposal-decorators", {
+      "legacy": true
+    }],
+    [
+      "@babel/plugin-proposal-class-properties",
+      { "loose": true }
+    ],
+    ["@babel/plugin-transform-react-jsx", {
+      "pragma": "h"
+    }]
   ]
 }

CHANGELOG.md

@@ -0,0 +1,64 @@
+### Preact Website Update
+
+**Size before:** _(via [size-plugin](https://github.com/googlechromelabs/size-plugin))
+
+WPT: https://www.webpagetest.org/result/181210_P8_82a008b7a17bc1c55c61197672205e93/
+LH: https://www.webpagetest.org/lighthouse.php?test=181210_P8_82a008b7a17bc1c55c61197672205e93&run=3
+
+```
+     a3d80eb575b803a6508e.worker.js ⏤  216 kB
+                          bundle.js ⏤  33.6 kB
+    1.80d97f20c0fd15d2e7c6.chunk.js ⏤  3.21 kB
+    2.f0ec73293bbbd9656786.chunk.js ⏤  8.77 kB
+ repl.96b61a2ae529b974054a.chunk.js ⏤  70.1 kB
+                          style.css ⏤  6.66 kB
+                         index.html ⏤  2.23 kB
+                              sw.js ⏤  10 kB (+2 B)
+             appcache/manifest.html ⏤  66 B
+```
+
+**Size After:**
+
+```
+     247ee39acd39bae81efc.worker.js ⏤  217 kB
+                          bundle.js ⏤  33.8 kB
+    1.********************.chunk.js ⏤  3.21 kB
+    2.********************.chunk.js ⏤  8.77 kB
+ repl.********************.chunk.js ⏤  71.9 kB (+1.71 kB)
+                          style.css ⏤  6.66 kB
+                         index.html ⏤  2.23 kB
+                              sw.js ⏤  10 kB (-8 B)
+             appcache/manifest.html ⏤  66 B
+```
+
+### RCA
+
+- bundle.js increased by 1.5kB because of marked: (+2kB to 7.2kB: https://bundlephobia.com/[email protected])
+- highlight.js increased in size dramatically over the past few releases, though we're subsetting
+- polyfills increased in size. switch from fetch to unfetch helped, code-splitting removed the issue entirely
+- classnames increased in size a bit. it also isn't getting bundled optimally due to a nonstandard UMD wrapper
+- FCP was always a bit bad since only the app shell is prerendered
+
+**After webpack + dep updates:**
+
+```
+ ae1ee828a2ca1fab34e4.worker.js ⏤  214 kB
+               editor.44a85.css ⏤  2.14 kB
+          editor.452bc.chunk.js ⏤  69 kB
+           emoji.d52cc.chunk.js ⏤  8.75 kB
+                 main.3b5f6.css ⏤  6.6 kB
+                        main.js ⏤  29.9 kB
+         offline.e400f.chunk.js ⏤  801 B
+                   polyfills.js ⏤  2.01 kB
+                 repl.45b46.css ⏤  899 B
+            repl.34587.chunk.js ⏤  2.28 kB
+                     index.html ⏤  2.22 kB
+                          sw.js ⏤  10.4 kB (+2 B)
+         appcache/manifest.html ⏤  86 B
+```
+
+| Metric      | Start  | Final  |
+|-------------|--------|--------|
+| FCP         | 1300ms | 1300ms |
+| TTI         | 5900ms | 2950ms |
+| Speed Index | 2380ms | 1910ms |