[big chore] restore core to monorepo (#287)

* move core into repo, apps into apps folder, update tests

* Update scripts for build:core

* improve scripts

* remove noise from www

* Update .gitignore

* Fix focus bug

* add ci test script

* Update main.yml

examples/tldraw-example/scripts/dev.mjs

@@ -0,0 +1,58 @@
+/* eslint-disable no-undef */
+import fs from 'fs'
+import path from 'path'
+import esbuildServe from 'esbuild-serve'
+import dotenv from 'dotenv'
+
+dotenv.config()
+
+async function main() {
+  if (fs.existsSync('./dist')) {
+    fs.rmSync('./dist', { recursive: true }, (e) => {
+      if (e) {
+        throw e
+      }
+    })
+  }
+
+  fs.mkdirSync('./dist')
+
+  fs.readdirSync('./src/public').forEach((file) =>
+    fs.copyFile(path.join('./src/public', file), path.join('./dist', file), (err) => {
+      if (err) throw err
+    })
+  )
+
+  try {
+    await esbuildServe(
+      {
+        entryPoints: ['src/index.tsx'],
+        outfile: 'dist/index.js',
+        minify: false,
+        bundle: true,
+        sourcemap: true,
+        incremental: true,
+        format: 'cjs',
+        target: 'es6',
+        define: {
+          'process.env.NODE_ENV': '"development"',
+          'process.env.LIVEBLOCKS_PUBLIC_API_KEY': `"${process.env.LIVEBLOCKS_PUBLIC_API_KEY}"`,
+        },
+        watch: {
+          onRebuild(err) {
+            err ? error('❌ Failed') : log('✅ Updated')
+          },
+        },
+      },
+      {
+        port: 5420,
+        root: './dist',
+        live: true,
+      }
+    )
+  } catch (err) {
+    process.exit(1)
+  }
+}
+
+main()