rename "usbstick" to "installation media" and move before wizard

Besides the fact that "usb stick" is germaenglisch it allows to move
that section up which brings the chapter in a better order, as one
needs to prepare the installation media before they can use the
installer itself ;-)

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

pve-installation-media.adoc

@@ -1,9 +1,12 @@
-Install from a USB Flash Drive
+[[installation_prepare_media]]
-------------------------------
+Prepare Installation Media
+--------------------------
 ifdef::wiki[]
 :pve-toplevel:
 endif::wiki[]
 
+Download the installer ISO image from: {website}en/downloads/category/iso-images-pve
+
 The {pve} installation media is a hybrid ISO image. It works in two ways:
 
 * An ISO image file ready to burn to a CD or DVD.
@@ -16,9 +19,6 @@ the faster option.
 Prepare a USB Flash Drive as Installation Medium
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Download the installer ISO image from:
-https://www.proxmox.com/en/downloads/category/iso-images-pve
-
 The flash drive needs to have at least 1 GB of storage available.
 
 NOTE: Do not use UNetbootin. It does not work with the {pve} installation image.
@@ -112,9 +112,12 @@ will show up. Click 'No'. In the next dialog select the 'DD' mode.
 An alternative to Rufus is Etcher. Download Etcher from https://etcher.io. It
 will guide you through the process of selecting the ISO and your USB Drive.
 
+ifdef::wiki[]
 Boot your Server from the USB Flash Drive
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 Connect the USB flash drive to your server and make sure that booting from USB
 is enabled (check your servers firmware settings). Then follow the steps in the
 xref:chapter_installation[installation wizard].
+
+endif::wiki[]

pve-installation.adoc

@@ -26,6 +26,8 @@ ifndef::wiki[]
 
 include::pve-system-requirements.adoc[]
 
+include::pve-installation-media.adoc[]
+
 endif::wiki[]
 
 
@@ -33,7 +35,7 @@ endif::wiki[]
 Using the {pve} Installer
 -------------------------
 
-Download the installer ISO at {website}en/downloads. It includes the following:
+The installer ISO image includes the following:
 
 * Complete operating system (Debian Linux, 64-bit)
 
@@ -50,8 +52,11 @@ Download the installer ISO at {website}en/downloads. It includes the following:
 NOTE: All existing data on the server will be removed during the installation
 process.
 
-Please insert the installation media (e.g. USB flash drive, CD-ROM) and boot
+Please insert the xref:installation_prepare_media[prepared installation media]
-from it.
+(for example, USB flash drive or CD-ROM) and boot from it.
+
+TIP: Make sure that booting from the installation medium (for example, USB) is
+enabled in your servers firmware settings.
 
 [thumbnail="screenshot/pve-grub-menu.png"]
 
@@ -276,8 +281,6 @@ endif::wiki[]
 
 ifndef::wiki[]
 
-include::pve-usbstick.adoc[]
-
 Install {pve} on Debian
 -----------------------