Use local built CSS and fonts for master documentation (#1584)

* Change `npm run` to `yarn`

* Export `commander` program if required as module

* Move `prestart` (cli.md generation) to build.js

* Normalize script names

* Change `yarn prestart` to `node lib/build.js`

* Use local built CSS and fonts

* Move stylesheet after the first paragraph

* Remove prestart script

website/lib/build.js

@@ -0,0 +1,16 @@
+const fs = require('fs-extra');
+
+// generate cli.md
+const cli = require('../../cli');
+const template = fs.readFileSync('../docs/cli.md.template');
+
+fs.writeFileSync('../docs/cli.md', [template,
+    ...cli.options.map(option => `### \`${option.flags}\`
+${option.description}${((option.bool && option.defaultValue !== undefined)
+? ' (default: ' + option.defaultValue + ')' : '')}
+`),
+    '### `-h, --help`\nOutput usage information', ''].join('\n'));
+
+// copy local built CSS and fonts
+fs.copySync('../dist/katex.min.css', 'static/static/katex.min.css');
+fs.copySync('../dist/fonts', 'static/static/fonts');