Add build steps to readme

README.md

@@ -91,3 +91,14 @@ Custom plugins also work for inline `<script>`s:
 ```html
 <script type="text/babel" data-plugins="lolizer">
 ```
+
+Manually Building
+=================
+
+If you want to manually upgrade the Babel version used by babel-standalone (or build your own release), follow these steps:
+
+1. Upgrade the Babel versions in `package.json`. This can be done with `npm-check-upgrades` (eg. `npm-check-updates -u -a --packageFile ./package.json /^babel\-/`)
+2. Delete `node_modules`, as npm often produces inefficient directory layouts if you upgrade in-place
+3. Run `npm run build`
+4. Run `npm run test` to ensure it works
+5. Open `examples/example.htm` and ensure it works