Optimize build to reduce wasm size 12% or so

Tested opt-level 'z' too, doesn't seem to make any difference.

Author: pimterry

Cargo.toml

@@ -13,6 +13,10 @@ crate-type = ["cdylib", "rlib"]
 [features]
 default = ["wee_alloc", "console_error_panic_hook"]
 
+[profile.release]
+lto = true
+opt-level = 's'
+
 [dependencies]
 wasm-bindgen = "0.2"
 brotli = "3.3"

build.js

@@ -6,6 +6,7 @@ if (!shell.which('wasm-pack')) {
 
 // Clean up any existing built content:
 shell.rm('-rf', 'dist');
+shell.rm('-rf', 'pkg.*');
 shell.mkdir('dist');
 
 // Create the bundler output