chore: Update README.md

README.md

-# txwrapper
+# @amaurymartiny/txwrapper
 
-Go to [documentation](https://github.com/amaurymartiny/txwrapper/tree/master/docs/globals.md).
+```bash
+yarn add @amaurymartiny/txwrapper
+```
+
+In a JS file:
+
+```typescript
+import { generateKeypair } from '@amaurymartiny/txwrapper';
+
+console.log(generateKeypair().address);
+```
+
+Go to [documentation](https://github.com/amaurymartiny/txwrapper/tree/master/docs/globals.md) for all the functions.