Fix some grammar. Add some additional notes for HTTPS and STUN servers

guides/advanced/debugging.md

@@ -161,3 +161,5 @@ You can also configure PeerConnection to use a specific port range by doing
 ```
 
 Otherwise, the connection won't be established at all, or just in one direction.
+
+Read more in our [Deploying tutorial](./deploying.md#allow-udp-traffic-in-your-firewall)!

guides/advanced/deploying.md

@@ -1,9 +1,9 @@
 # Deploying
 
-Deploying WebRTC applications might be cumbersome.
-Here are a couple of nitpicks you should keep in mind when trying to push your project into production.
+Deploying WebRTC applications can be cumbersome.
+Here are a couple of details you should keep in mind when trying to push your project into production.
 
-### Allow for UDP traffic in your firewall
+## Allow UDP traffic in your firewall
 
 In most cases, WebRTC uses UDP to exchange audio and video data.
 Therefore, you have to allow UDP traffic in your firewall.
@@ -20,12 +20,12 @@ However, you can specify an exact port range that ICE will use when creating a n
 PeerConnection.start_link(ice_port_range: 50_000..60_000)
 ```
 
-### Allow for TCP traffic in your firewall
+## Allow TCP traffic in your firewall
 
 In some cases, when ICE really cannot find a UDP path, it may fall back to a TCP connection.
 However, since our ICE implementation does not support TCP yet, you don't need to take any extra steps here :)
 
-### Export ports in your docker container
+## Export ports in your Docker container
 
 If you are running your application using Docker, we recommend using the `--network host` option.
 If that's not possible (e.g. you are running on macOS), you have to manually export the ports used by ICE, e.g.:
@@ -34,23 +34,24 @@ If that's not possible (e.g. you are running on macOS), you have to manually exp
 docker run -p 50000-50010/udp myapp
 ```
 
-Keep in mind that exporting a lot of ports might take a lot of time or even cause the Docker deamon to timeout.
+Keep in mind that exporting a lot of ports might take a lot of time or even cause the Docker daemon to timeout.
 That's why we recommend using host's network.
 
-### Choose your cloud provider wisely
+## Choose your cloud provider wisely
 
 Many cloud providers do not offer good support for UDP traffic.
 In such cases, deploying a WebRTC-based application might be impossible.
 We recommend using bare machines that you can configure as you need.
 
-### Enable HTTPS in your frontend
+## Enable HTTPS in your frontend
 
 The server hosting your frontend site must have HTTPS enabled.
 This is a requirement for accessing the user's microphone and camera devices.
+Not using HTTPS on addresses different than localhost will result in `navigator.mediaDevices` being `null`.
 
-### Proxy WebSocket connections
+## Proxy WebSocket connections
 
-WebSockets are a common option for signalling channel.
+WebSockets are a common option for the signalling channel.
 If you are using a reverse-proxy like nginx, to make your WebSocket connections work,
 you have to preserve the original (client) request headers.
 In other words, you need to add the following lines to your endpoint handling websocket connections configuration:
@@ -63,7 +64,7 @@ proxy_set_header Connection "upgrade";
 
 Read more [here](https://nginx.org/en/docs/http/websocket.html).
 
-### Configure STUN servers
+## Configure STUN servers
 
 If you are deploying your application behind a NAT, you have to configure a STUN 
 server that will allow it to discover its public IP address.
@@ -76,9 +77,12 @@ PeerConnection.start_link(ice_servers: [%{urls: "stun:stun.l.google.com:19302"}]
 Google's STUN server is publicaly available, but keep in mind that you depend on
 someone else's infrastructure.
 If it goes down, you can do nothing about it.
-Anyway, that's what a lot of people do :) 
+To avoid that, you would need to host your own STUN server.
+Keep in mind, that TURN servers are also STUN servers so if you have already TURN deployed,
+you don't need to specify additional STUN servers.
+And as a TURN server, you can always use our [Rel](https://github.com/elixir-webrtc/rel)!
 
-### Configure TURN servers
+## Configure TURN servers
 
 If your application is deployed behind a very restrictive NAT, which should be very rare (e.g. a symmetric NAT),
 you will need to configure a TURN server.