remove ResizeObserver ponyfill. fixes #28

package.json

@@ -25,7 +25,6 @@
   },
   "dependencies": {
     "hyperx-tmp": "^2.5.4",
-    "resize-observer-polyfill": "^1.5.1",
     "snabbdom": "^3.0.3"
   },
   "engines": {

readme.md

@@ -67,7 +67,7 @@ html`<div data-breakpoints='{ "BP1": 400, "BP2": 600, "BP3": 1200 }'> Some conte
 
 If the div is 700px wide, it will have `BP2` in it's classlist. Only the class with the highest matching rule will be added, regardless of what order the rules are declared in.
 
-Internally, this is implemented with a ResizeObserver, and that is ponyfilled to support older browsers.
+Internally, this is implemented with a ResizeObserver. As of version 5, we no longer bundle a ResizeObserver ponyfill with snabby. You should polyfill ResizeObserver yourself if you plan on using snabby on very old browsers.   https://www.npmjs.com/package/resize-observer-polyfill
 
 
 ### Directives

snabbdom-containerquery.js

@@ -1,15 +1,5 @@
 // inspired by https://philipwalton.com/articles/responsive-components-a-solution-to-the-container-queries-problem/
 
-// ResizeObserver support is pretty good, but about 10% of the browsers still lack it.
-// in some cases, snabbdom is used as a 3rd party module that gets used on websites,
-// and it's unacceptable in some cases to install global polyfills.
-//
-// for now we inline it into the plugin as a ponyfill so that it's always available,
-// doesn't pollute global scope, and works in almost all in-use browsers, at the cost of a few kb.
-//
-// https://github.com/que-etc/resize-observer-polyfill
-import ResizeObserver from 'resize-observer-polyfill';
-
 
 // today it's more performant to have 1 resizeObserver observe multiple elements rather than 1 per element.
 // see https://groups.google.com/a/chromium.org/g/blink-dev/c/z6ienONUb5A/m/F5-VcUZtBAAJ