fix: cleanup dist folder, change README

- move images for README into docs/img
- move libs/* into utils. libs folder is copied into dist by grafana-toolkit
- remove d3-scale-chromatic sources, use it from dependencies
- update compatible versions in README
- update installation info

webpack.config.js

@@ -0,0 +1,15 @@
+// Copy screenshots defined in plugin.json.
+
+const path = require('path');
+const pluginJson = require(path.resolve(process.cwd(), 'src/plugin.json'));
+const CopyWebpackPlugin = require('copy-webpack-plugin');
+
+module.exports.getWebpackConfig = (config, options) => ({
+  ...config,
+  plugins: [...config.plugins, new CopyWebpackPlugin(
+    pluginJson.info.screenshots.map(function(item) {
+      return {from: "../docs/"+item.path, to: "./img"}
+    }),
+    { logLevel: options.watch ? 'silent' : 'warn' }
+  ) ],
+});