docs: share --reload-systemd option between quadlet install and rm

Extract the --reload-systemd option text into a shared option file
at docs/source/markdown/options/reload-systemd.md and reference it
with @@option in both podman-quadlet-install and podman-quadlet-rm
manpages, following the established pattern for shared options.

Rename the manpages from .md to .md.in to indicate preprocessing.

Fixes #28370

Signed-off-by: Kit Dallege <xaum.io@gmail.com>

docs/source/markdown/options/reload-systemd.md

@@ -0,0 +1,9 @@
+####> This option file is used in:
+####>   podman quadlet install, quadlet rm
+####> If file is edited, make sure the changes
+####> are applicable to all of those.
+#### **--reload-systemd**
+
+Reload systemd after the operation completes (default true).
+In order to disable it users need to manually set the value
+of this flag to `false`.

docs/source/markdown/podman-quadlet-install.1.md.in

@@ -37,11 +37,7 @@ directory with the application name. The application name is required when
 specifying a directory path. An application name can't have a quadlet extension
 as suffix. For example `foo.container` isn't a valid application name.
 
-#### **--reload-systemd**
-
-Reload systemd after installing Quadlets (default true).
-In order to disable it users need to manually set the value
-of this flag to `false`.
+@@option reload-systemd
 
 #### **--replace**, **-r**
 

docs/source/markdown/podman-quadlet-rm.1.md.in

@@ -33,11 +33,7 @@ Do not error for Quadlets that do not exist.
 
 Required when removing applications (default false).
 
-#### **--reload-systemd**
-
-Reload systemd after removing Quadlets (default true).
-In order to disable it users need to manually set the value
-of this flag to `false`.
+@@option reload-systemd
 
 ## EXAMPLES