docs: update pasta options description

First, remove wrong sentence that says ports are forwarded dynamically
by default. That is wrong and contradicts what is written below.
Second, document that we also set --dns-forward and --map-guest-addr by
default. And lastly document the containers.conf field so users know
they are not forced to set the options on each command.

Signed-off-by: Paul Holzinger <[email protected]>

Author: Luap99

docs/source/markdown/options/network.md

@@ -51,9 +51,7 @@ Valid _mode_ values are:
     stack. \
     This is the default for rootless containers and only supported in rootless mode. \
     By default, IPv4 and IPv6 addresses and routes, as well as the pod interface
-    name, are copied from the host. If port forwarding isn't configured, ports
-    are forwarded dynamically as services are bound on either side (init
-    namespace or container namespace). Port forwarding preserves the original
+    name, are copied from the host. Port forwarding preserves the original
     source IP address. Options described in pasta(1) can be specified as
     comma-separated arguments. \
     In terms of pasta(1) options, **--config-net** is given by default, in
@@ -62,11 +60,20 @@ Valid _mode_ values are:
     container to host using the gateway address. The latter can be overridden
     by passing **--map-gw** in the pasta-specific options (despite not being an
     actual pasta(1) option). \
+    For better integration with DNS handling, **--dns-forward 169.254.1.1** is passed,
+    and this address is added to resolv.conf(5) as first resolver. It is possible to pass
+    **--dns-forward** explicitly in case a different IP address should be used.
+    To make the `host.containers.internal` /etc/hosts entry work and allow connections
+    to the host, **--map-guest-addr 169.254.1.2** is passed. Again, it can be set
+    explicitly to choose a different IP address. \
     Also, **-t none** and **-u none** are passed if, respectively, no TCP or
-    UDP port forwarding from host to container is configured, to disable
-    automatic port forwarding based on bound ports. Similarly, **-T none** and
-    **-U none** are given to disable the same functionality from container to
+    UDP port forwarding from host to container is configured (via Podman's
+    **--publish** or by passing the pasta **-t**/**-u** options directly),
+    to disable automatic port forwarding based on bound ports. Similarly, **-T none**
+    and **-U none** are given to disable the same functionality from container to
     host. \
+    All options can also be set in **[containers.conf(5)](https://github.com/containers/common/blob/main/docs/containers.conf.5.md)**;
+    see the `pasta_options` key under the network section in that file. \
     Some examples:
     - **pasta:--map-gw**: Allow the container to directly reach the host using the
         gateway address.