add build script for esbuild

Author: RobinMalfait

scripts/build.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+# Find all .js files
+FILES=$(find -E ./src -regex ".*.js")
+
+# Compile with esbuild
+esbuild $FILES --minify --outdir=lib --platform=node --format=cjs --target=node12
+
+# A bit annoying, but let's copy the css file that we require
+mkdir -p ./lib/plugins/css
+cp ./src/plugins/css/preflight.css ./lib/plugins/css/preflight.css