Custom Certificates

## What is your suggestion?
Within the documentation, it mentions that the below to add your own cert:

```bash
# Replaces "cert: false" with "cert: true" in the code-server config.
sed -i.bak 's/cert: false/cert: true/' ~/.config/code-server/config.yaml
# Replaces "bind-addr: 127.0.0.1:8080" with "bind-addr: 0.0.0.0:443" in the code-server config.
sed -i.bak 's/bind-addr: 127.0.0.1:8080/bind-addr: 0.0.0.0:443/' ~/.config/code-server/config.yaml
# Allows code-server to listen on port 443.
sudo setcap cap_net_bind_service=+ep /usr/lib/code-server/lib/node
```

It finishes with the final statement regarding the `cert` and `cert-key` config fields.

```text
If you'd like to avoid the warnings displayed by code-server when using a self-signed certificate, you can use [mkcert](https://mkcert.dev/) to create a self-signed certificate that's trusted by your operating system, then pass the certificate to code-server via the cert and cert-key config fields.
```
**Issue:** when installing via ubuntu to change the `config.yaml` file, the docs just mentions to pass in the fields which I understand to modify the `config.yaml` file but its not clear. Nor does it state that the `cert:true` field should **ACTUALLY** be changes to the *directory of the .pem/.crt* file not a boolean value.

## How will this improve the docs?

This will clearly state that the `config.yaml` file should be modified and to pass in the directory of the `your-cert.pem` file into the cert field instead of a boolean value

## Are you interested in submitting a PR for this?
Sure!