✨ Add WhatsApp integration beta test (#722)

Related to #401

apps/docs/docs/embed/whatsapp.md

@@ -0,0 +1,31 @@
+# WhatsApp
+
+WhatsApp is currently available as a private beta test. If you'd like to try it out, reach out to support@typebot.io.
+
+## Preview
+
+You can preview and test your bot by clicking on the Preview button in the editor and change the runtime to "WhatsApp".
+
+## Publish
+
+Head over to the Share tab of your bot and click on the WhatsApp button to get the integration instructions of your bot.
+
+## Limitations
+
+WhatsApp environment have some limitations that you need to keep in mind when building the bot:
+
+- GIF and SVG image files are not supported. They won't be displayed.
+- Buttons content can't be longer than 20 characters
+- Incompatible blocks, if present, they will be skipped:
+  - Payment input block
+  - Chatwoot block
+  - Script block
+  - Google Analytics block
+  - Meta Pixel blocks
+  - Execute on client options
+
+## Contact information
+
+You can automatically assign contact name and phone number to a variable in your bot using a Set variable block with the dedicated system values:
+
+<img src="/img/whatsapp/contact-var.png" alt="WhatsApp contact system variables" />