Added readme

readme.md

@@ -1,2 +1,25 @@
 # browser-ext-react-esbuild
 
+See article on [dev.to](https://dev.to/bingqiao/creating-a-browser-extension-for-safari-and-chrome-493m).  
+
+Run `npm install` first.
+
+To build this extension for Chrome:
+```
+npm run package
+```
+Then load `dist` as unpacked extension for Chrome.
+
+To build for Safari:
+```
+npm run deploy
+```
+The above will build the same extension resources in `dist`, then copy its  
+contents to the extension "Resources" folder of the Swift project [browser-ext](https://github.com/bingqiao/browser-ext).
+
+Together the two projects serve as a template of creating browser extension  
+for both Safari and Chrome (possibly Mozilla Firefox, but not tested) using  
+React, TypeScript and esbuild.
+
+The full AutoRefresh app (free and without Ads) implemented in a similar way  
+can be found in App store [download](https://apps.apple.com/gb/app/autorefresh/id1592466003) (free and no Ads).