Create build step for the web server (#289)

* Create build step for the web server

* Update bskyweb routes and 404 behavior

scripts/post-web-build.js

@@ -0,0 +1,27 @@
+const path = require('path')
+const fs = require('fs')
+
+const projectRoot = path.join(__dirname, '..')
+const webBuildJs = path.join(projectRoot, 'web-build', 'static', 'js')
+const templateFile = path.join(
+  projectRoot,
+  'bskyweb',
+  'templates',
+  'scripts.html',
+)
+
+const jsFiles = fs.readdirSync(webBuildJs).filter(name => name.endsWith('.js'))
+jsFiles.sort((a, b) => {
+  // make sure main is written last
+  if (a.startsWith('main')) return 1
+  if (b.startsWith('main')) return -1
+  return a.localeCompare(b)
+})
+
+console.log(`Found ${jsFiles.length} js files in web-build`)
+console.log(`Writing ${templateFile}`)
+
+const outputFile = jsFiles
+  .map(name => `<script defer="defer" src="/static/js/${name}"></script>`)
+  .join('\n')
+fs.writeFileSync(templateFile, outputFile)