Update installation docs (#1650)

Include CentOS 9 Stream and CentOS 8 Stream, in addition to updating the
openSUSE instructions to cover upstream vagrant package installation.

Closes: #1429
Closes: #1537

docs/troubleshooting.markdown

@@ -0,0 +1,41 @@
+---
+title: Troubleshooting
+nav_order: 7
+toc: true
+---
+
+The first step for troubleshooting a VM image that appears to not boot correctly,
+or hangs waiting to get an IP, is to check it with a VNC viewer. A key thing
+to remember is that if the VM doesn't get an IP, then vagrant can't communicate
+with it to configure anything, so a problem at this stage is likely to come from
+the VM, but we'll outline the tools and common problems to help you troubleshoot
+that.
+
+By default, when you create a new VM, a vnc server will listen on `127.0.0.1` on
+port `TCP5900`. If you connect with a vnc viewer you can see the boot process. If
+your VM isn't listening on `5900` by default;
+
+ * Check the create domain details outputted to the console, or
+ * Use `virsh dumpxml` to find out which port it's listening on, or
+ * Explicitly configure it with `graphics_port` and `graphics_ip`
+   (see ['Domain Specific Options']({{ '/configuration#domain-specific-options' | relative_url }})).
+
+Note: Connecting with the console (`virsh console`) requires additional config,
+so some VMs may not show anything on the console at all, instead displaying it in
+the VNC console. The issue with the text console is that you also need to build the
+image used to tell the kernel to output to the console during boot, and typically
+most do not have this built in.
+
+Problems we've seen in the past include:
+- Forgetting to remove `/etc/udev/rules.d/70-persistent-net.rules` before packaging
+the VM
+- VMs expecting a specific disk device to be connected
+
+If you're still confused, check the Github Issues for this repo for anything that
+looks similar to your problem.
+
+[Github Issue #1032](https://github.com/vagrant-libvirt/vagrant-libvirt/issues/1032)
+contains some historical troubleshooting for VMs that appeared to hang.
+
+Did you hit a problem that you'd like to note here to save time in the future?
+Please do!