feat: add export subscribers scripts (#680)

* feat: add export subscibers scripts

* fix: replace code with gist link

concepts/subscribers.mdx

@@ -191,3 +191,28 @@ Novu will create a subscriber if one does not exist and will update the existing
 
 You can create subscribers in bulk _(up to 500 at once)_ via the SDKs or [API](/api-reference/subscribers/bulk-create-subscribers).
 
+## Export Subscribers
+
+Currently, Novu does not support exporting subscribers. However, [Get Subscribers API](/api-reference/subscribers/get-subscribers) can be used to fetch subscribers
+
+<Tabs>
+<Tab title="Node.js">
+### Steps:
+- `mkdir export_novu_subscribers`
+- `cd export_novu_subscribers`
+- create `fetch_subscribers.js` file and copy [export_novu_subscribers.js](https://gist.github.com/jainpawan21/8604b4b2c1582b419e837bdc72290696#file-export_novu_subscribers-js) gist code into this file.
+- `npm init -y`
+- `npm install axios fast-csv fs`
+- Run `node fetch_subscribers.js`
+- Subscribers are exported in `subscribers.csv` file
+
+</Tab>
+
+<Tab title="Shell Script">
+### Steps:
+- Create file with name fetch_subscribers.sh and copy [export_novu_subscribers.sh](https://gist.github.com/jainpawan21/8604b4b2c1582b419e837bdc72290696#file-export_novu_subscribers-sh) gist code into this file.
+- Run `chmod +x fetch_subscribers.sh`
+- Run `./fetch_subscribers.sh`
+- Subscribers are exported in `subscribers.csv` file
+</Tab>
+</Tabs>