docs: improve url_prefix docs and public domain override

website/docs/config.md

@@ -155,7 +155,7 @@ The prefix is intended to be used when the server runs behinds the proxy, check
 url_prefix: /verdaccio/
 ```
 
-> Verdaccio 5 has an improved prefix behaviour, [check here details](https://verdaccio.org/blog/2021/04/14/verdaccio-5-migration-guide#url_prefix-improved-behavior).
+> Verdaccio 5 has an improved prefix behaviour and the `VERDACCIO_PUBLIC_URL` is avilable for use, learn how to [here](https://verdaccio.org/blog/2021/04/14/verdaccio-5-migration-guide#url_prefix-improved-behavior).
 
 ### Max Body Size {#max-body-size}
 

website/docs/reverse-proxy.md

@@ -194,3 +194,34 @@ location ~ ^/verdaccio/(.*)$ {
 For this case, `url_prefix` should set to `/verdaccio/`
 
 > Note: There is a slash after the install path (`https://your-domain:port/verdaccio/`)!
+
+### Overriding the public url
+
+> Since `verdaccio@5.0.0`
+
+
+The new `VERDACCIO_PUBLIC_URL` is intended to be used behind proxies, this variable will be used for:
+
+- Used as base path to serve UI resources as (js, favicon, etc)
+- Used on return metadata `dist` base path
+- Ignores `host` and `X-Forwarded-Proto` headers
+- If `url_prefix` is defined would be appened to the env variable.
+
+```
+VERDACCIO_PUBLIC_URL='https://somedomain.org';
+url_prefix: '/my_prefix'
+
+// url -> https://somedomain.org/my_prefix/
+
+VERDACCIO_PUBLIC_URL='https://somedomain.org';
+url_prefix: '/'
+
+// url -> https://somedomain.org/
+
+VERDACCIO_PUBLIC_URL='https://somedomain.org/first_prefix';
+url_prefix: '/second_prefix'
+
+// url -> https://somedomain.org/second_prefix/'
+```
+
+![Screenshot from 2021-03-24 20-20-11](https://user-images.githubusercontent.com/558752/112371003-5fa1ce00-8cde-11eb-888c-70c4e9776c57.png)