doc: double the memory allocated to kvm in quickstart guide

Although 1GiB of RAM seems enough to install a server ISO and boot it
after, if feels rather on the low end nowadays.
The quickstart for s390x already uses 2GiB so it feels right to update
the generic guide to use 2GiB as well.

Signed-off-by: Olivier Gayot <olivier.gayot@canonical.com>

documentation/autoinstall-quickstart.md

@@ -50,7 +50,7 @@ python3 -m http.server 3003</code></pre>
 
 ### Run the install!
 
-<pre><code>kvm -no-reboot -m 1024 \
+<pre><code>kvm -no-reboot -m 2048 \
     -drive file=image.img,format=raw,cache=none,if=virtio \
     -cdrom ~/Downloads/ubuntu-22.10-live-server-amd64.iso \
     -kernel /mnt/casper/vmlinuz \
@@ -61,7 +61,7 @@ This will boot, download the config from the server set up in the previous step
 
 ### Boot the installed system
 
-<pre><code>kvm -no-reboot -m 1024 \
+<pre><code>kvm -no-reboot -m 2048 \
     -drive file=image.img,format=raw,cache=none,if=virtio</code></pre>
 
 This will boot into the freshly installed system and you should be able to log in as ubuntu/ubuntu.
@@ -102,7 +102,7 @@ cloud-localds ~/seed.iso user-data meta-data</code></pre>
 
 ### Run the install!
 
-<pre><code>kvm -no-reboot -m 1024 \
+<pre><code>kvm -no-reboot -m 2048 \
     -drive file=image.img,format=raw,cache=none,if=virtio \
     -drive file=~/seed.iso,format=raw,cache=none,if=virtio \
     -cdrom ~/Downloads/ubuntu-22.10-live-server-amd64.iso</code></pre>
@@ -115,7 +115,7 @@ The whole process should take about 5 minutes.
 
 ### Boot the installed system
 
-<pre><code>kvm -no-reboot -m 1024 \
+<pre><code>kvm -no-reboot -m 2048 \
     -drive file=image.img,format=raw,cache=none,if=virtio</code></pre>
 
 This will boot into the freshly installed system and you should be able to log in as ubuntu/ubuntu.