Merge branch 'update-images' into 'master'

Add Rocky and Alma to image list.

See merge request !307

static/markdown/anvil-images.md

 |       Image Name         |  Username to Connect  |        Access instructions           |                                 Description                                       |
 | ------------------------ | --------------------- | ------------------------------------ | --------------------------------------------------------------------------------- |
+| Alma Linux 8.5           |  `almalinux`          | `ssh -l almalinux@<ip address>`      | AlmaLinux is a free and open source Linux distribution that is binary-compatible with Red Hat Enterprise Linux (RHEL).|
 | Cloudera 5.12 GNOME      |  `cloudera`           | [X2Go instructions](/anvil/connecting_to_linux_instances_using_x2go/) | Cloudera 5.12 QuickStart VM. *Note*: Follow the X2Go instructions, but choose GNOME for the Session type instead of Xfce.|
 | CentOS 7.4               |   `centos`            | `ssh -l centos@<ip address>`         | The CentOS Linux distribution is a stable, predictable, manageable and reproducible platform derived from the sources of Red Hat Enterprise Linux (RHEL).|
 | CentOS 7.8               |   `centos`            | `ssh -l centos@<ip address>`         | The CentOS Linux distribution is a stable, predictable, manageable and reproducible platform derived from the sources of Red Hat Enterprise Linux (RHEL).|
@@ -9,6 +10,7 @@
 | Fedora 33 Cloud          |   `fedora`            | `ssh -l fedora <ipaddress>`          | Fedora is a Linux distribution developed by the community-supported Fedora Project and sponsored by the Red Hat company.|
 | Fedora 32 Xfce           |   `fedora`            | [X2Go instructions](/anvil/connecting_to_linux_instances_using_x2go/) | Fedora 28 with the Xfce Desktop Environment pre-installed.|
 | Fedora 32 RStudio (Xfce) |   `fedora`            | [X2Go instructions](/anvil/connecting_to_linux_instances_using_x2go/) | Fedora 28 with Rstudio and Xfce pre-installed.|
+| Rocky Linux 8.5          |   `rocky`             | `ssh -l rocky@<ip address>`          | Rocky Linux is an open-source enterprise operating system designed to be 100% bug-for-bug compatible with Red Hat Enterprise Linux. |
 | Windows 10	           |   `.\cloud-user`      | [Windows instructions](/anvil/connecting_to_windows_instances)       | Windows 10 LTSC edition with remote desktop access.|
 | Windows 10 Matlab	   |  `.\cloud-user`       | [Windows instructions](/anvil/connecting_to_windows_instances)       | Windows 10 LTSB with Matlab r2013b, r2014b, r2015b, r2016b, r2017a pre-installed. |
 | Windows 10 Matlab r2018b/r2019b | `.\cloud-user` | [Windows instructions](/anvil/connecting_to_windows_instances)       | Windows 10 LTSC with Matlab r2018b and r2019b pre-installed. |