Change Caddy links (old is deprecated) (#7789)

* Change Caddy links

Current links points to Caddy v1 which is deprecated.

Signed-off-by: Nicolai Søborg <git@xn--sb-lka.org>

README.rst

@@ -215,7 +215,7 @@ Using a reverse proxy with Synapse
 It is recommended to put a reverse proxy such as
 `nginx <https://nginx.org/en/docs/http/ngx_http_proxy_module.html>`_,
 `Apache <https://httpd.apache.org/docs/current/mod/mod_proxy_http.html>`_,
-`Caddy <https://caddyserver.com/docs/proxy>`_ or
+`Caddy <https://caddyserver.com/docs/quick-starts/reverse-proxy>`_ or
 `HAProxy <https://www.haproxy.org/>`_ in front of Synapse. One advantage of
 doing so is that it means that you can expose the default https port (443) to
 Matrix clients without needing to run Synapse with root privileges.

changelog.d/7789.doc

+Update doc links for caddy. Contributed by Nicolai Søborg.

docs/reverse_proxy.md

@@ -3,7 +3,7 @@
 It is recommended to put a reverse proxy such as
 [nginx](https://nginx.org/en/docs/http/ngx_http_proxy_module.html),
 [Apache](https://httpd.apache.org/docs/current/mod/mod_proxy_http.html),
-[Caddy](https://caddyserver.com/docs/proxy) or
+[Caddy](https://caddyserver.com/docs/quick-starts/reverse-proxy) or
 [HAProxy](https://www.haproxy.org/) in front of Synapse. One advantage
 of doing so is that it means that you can expose the default https port
 (443) to Matrix clients without needing to run Synapse with root