Option to not inject `.css` in `index.html` during build

Thanks for a great vite plugin. :clap:

When using cesium.js in a lazy loaded JavaScript bundle, cesium({ rebuildCesium: true }) works well since https://github.com/nshen/vite-plugin-cesium/blob/3eefe025fbe186e7051fee88b30418d948dec43a/src/index.ts#L110-L117 ensures the <script...> tag is not included in the index.html, and therefore also cesium.js (which is quite large in size) is not loaded when visiting the main entrypoint of the application.

I think it would be beneficial to also have the plugin option to not inject the stylesheet link, i.e. https://github.com/nshen/vite-plugin-cesium/blob/3eefe025fbe186e7051fee88b30418d948dec43a/src/index.ts#L100-L108

Use case arguments: 1) When lazy loading cesium.js, it would be nice to also lazy load the associated cesium CSS file, which is quite large (30 kB) and unhashed (i.e. can't be cached safely). For projects who want to lazy load the .css this is easily accomplished by importing the css as well

   import "cesium/Build/Cesium/Widgets/widgets.css";

in the source code where import * as Cesium from "cesium"; is already imported (maybe adding this assoicated css import can even be done automatically by the vite plugin when rebuildCesium: true, before vite/rollup do their bundling?). The required cesium .css then goes through all the vite machinery for minimizing/lazy-chunking it... 2) ...which then also puts it into a hashed file, which ensures the cesium css can also be strongly cached, instead of having to load it every time (without hash you would have problems when updating cesium later).

Current "workaround" is to remove the injected <link rel="stylesheet" href="/cesium/Widgets/widgets.css"> line in the generated index.html, and instead ensure the .css is added to the vite generated .css bundle by adding import "cesium/Build/Cesium/Widgets/widgets.css";

nshen / vite-plugin-cesium

Option to not inject `.css` in `index.html` during build #51