Docs update for Ubuntu 20.04 LTS support

.github/ISSUE_TEMPLATE/bug-report.md

@@ -15,7 +15,7 @@ A clear and concise description of what the bug is.
 **Environment**
 - Ansible-NAS revision (`git rev-parse --short HEAD`):
 - Ansible version (paste the entire output of `ansible --version` on the machine you run the playbook from):
-- Ansible-NAS operating system (`cat /etc/lsb-release` on the Ansible-NAS box) - _If this is anything other than Ubuntu 18.04 help will be limited_:
+- Ansible-NAS operating system (`cat /etc/lsb-release` on the Ansible-NAS box) - _Support won't be provided for non-LTS releases of Ubuntu_:
 - Ansible-NAS kernel (`uname -a` on the Ansible-NAS box):
 - Ansible-NAS Python version (`python --version` on the Ansible-NAS box):
 - Ansible-NAS Docker version (`docker --version` on the Ansible-NAS box):

README.md

@@ -131,7 +131,7 @@ Assuming that your Ubuntu system disk is separate from your storage (it should b
 ## Requirements
 
 * Ansible NAS targets the latest Ubuntu LTS release, which is currently Ubuntu
-  Server 18.04.3 LTS.
+  Server 20.04 LTS.
 * You can run Ansible-NAS on whatever you like, read the docs for more info. I
   use an HP Microserver.
 

docs/overview.md

@@ -56,10 +56,10 @@ As a to-do list, before you can even install Ansible-NAS, you'll have to:
    account it [loves RAM](zfs/zfs_overview.md) and prefers to have the hard
    drives all to itself.
 
-1. Install **Ubuntu Server**, currently 18.04 LTS, and keep it updated. You'll
+1. Install **Ubuntu Server**, currently 20.04 LTS, and keep it updated. You'll
    probably want to perform other basic setup tasks like hardening SSH and
    including email notifications. There are [various
-   guides](https://devanswers.co/ubuntu-18-04-initial-server-setup/) for this,
+   guides](https://devanswers.co/ubuntu-20-04-initial-server-setup/) for this,
    but if you're just getting started, you'll probably need a book.
 
 You will probably want to install a specialized filesystem for bulk storage such

docs/zfs/zfs_configuration.md

@@ -36,9 +36,9 @@ Ansible-NAS storage. These two drives will be **mirrored** to provide
 redundancy. The actual Ubuntu system will be on a different drive and is not our
 concern.
 
-> [Root on ZFS](https://github.com/zfsonlinux/zfs/wiki/Ubuntu-18.04-Root-on-ZFS)
-> is still a hassle for Ubuntu. If that changes, this document might be updated
-> accordingly. Until then, don't ask us about it.
+> [Root on ZFS](https://openzfs.github.io/openzfs-docs/Getting%20Started/Ubuntu/Ubuntu%2020.04%20Root%20on%20ZFS.html)
+is possible, but not something that has been tested with Ansible-NAS.
+
 
 The Ubuntu kernel is already ready for ZFS. We only need the utility package
 which we install with `sudo apt install zfsutils`.