improve build.

build.js

@@ -4,6 +4,8 @@ const esbuild = require('esbuild')
 const alias = require('esbuild-plugin-alias')
 const nodeGlobals = require('@esbuild-plugins/node-globals-polyfill').default
 
+const prod = process.argv.indexOf('prod') !== -1
+
 esbuild
   .build({
     bundle: true,
@@ -21,7 +23,7 @@ esbuild
       }),
       nodeGlobals({buffer: true})
     ],
-    sourcemap: 'inline',
+    sourcemap: prod ? false : 'inline',
     define: {
       global: 'window'
     }

package.json

@@ -14,8 +14,9 @@
     "webextension-polyfill": "^0.8.0"
   },
   "scripts": {
-    "build": "./build.js",
+    "build": "./build.js prod",
     "watch": "ag -l --js | entr ./build.js",
+    "sources": "rm -f extension/*.build.*; zip -r sources . -i extension build.js README.md",
     "package": "cd extension; zip -r archive *; cd ..; mv extension/archive.zip ./nos2x.zip"
   }
 }