Add build script and instructions

.gitignore

@@ -0,0 +1,2 @@
+# Project
+/dist/

Makefile

@@ -0,0 +1,20 @@
+.PHONY: all clean element-web static
+
+all: clean element-web static
+
+element-web:
+	cd 'element-web' \
+	&& yarn install --frozen-lockfile \
+	&& yarn build \
+	&& mkdir --parents '../dist' \
+	&& rsync --checksum --itemize-changes --recursive \
+		'webapp/' '../dist/'
+
+static:
+	rsync --checksum --itemize-changes --recursive \
+		'static/' 'dist/'
+
+clean:
+	rm --force --recursive \
+		'dist' \
+		'element-web/webapp'

README.md

@@ -1,3 +1,34 @@
 # attend.seagl.org
 
 Web interface to the SeaGL 2021 virtual conference
+
+## Development
+
+Install dependencies:
+
+- [Node.js] (latest LTS)
+- [Yarn]
+- [Make]
+- [rsync]
+- a local web server, such as [serve] or Python’s [`http.server`][http.server]
+
+Build the static site:
+
+```bash
+make
+```
+
+Serve it at e.g. [`localhost:8000`](http://localhost:8000/):
+
+```bash
+python -m 'http.server' --directory 'dist'
+```
+
+[cloudfront]: https://aws.amazon.com/cloudfront/
+[http.server]: https://docs.python.org/3/library/http.server.html
+[make]: https://www.gnu.org/software/make/
+[node.js]: https://nodejs.org/
+[rsync]: https://rsync.samba.org/
+[s3]: https://aws.amazon.com/s3/
+[serve]: https://github.com/vercel/serve
+[yarn]: https://yarnpkg.com/