Move all remote dependencies to be local (#220)

* Experiment with javascript bundling

* Experiment with snowpack. Making progress

* Success!  Uses local js modules and assets and no cdns

* Missing local css

webroot/js/components/chat/content-editable.js

@@ -6,7 +6,7 @@ and here:
 https://stackoverflow.com/questions/22677931/react-js-onchange-event-for-contenteditable/27255103#27255103
 
 */
-import { Component, createRef, h } from 'https://unpkg.com/preact?module';
+import { h, Component, createRef } from '/js/web_modules/preact.js';
 
 export function replaceCaret(el) {
   // Place the caret at the end of the element