doc: Add Documentation for podman usage via TESSERACT_DOCKER_EXECUTABLE (#324)

#### Relevant issue or PR
Fixes #8

#### Description of changes
I did not document the usage of `--no-compose` as this will be
deprecated with the next release. Similarly, I removed the requirement
to install `docker-compose`.

#### Testing done
N/A

---------

Co-authored-by: Dion Häfner <dion.haefner@simulation.science>

Author: jpbrodrick89

docs/content/creating-tesseracts/deploy.md

@@ -43,6 +43,9 @@ $ docker run vectoradd serve
 
 This provides fine-grained control over the Tesseract image, and allows you to use any container-aware tooling to manage and deploy them.
 
+```{tip}  As the `podman` API is fully compatible with `docker`, the above should still work if `docker` is replaced with `podman`.
+```
+
 ## Example: Deploying a Tesseract on [Azure Virtual Machines](https://azure.microsoft.com/en-us/products/virtual-machines)
 
 ```{note}

docs/content/introduction/installation.md

@@ -26,10 +26,9 @@ If the output is an empty table, that's okay! The CLI is functioning correctly,
 [Docker Desktop](https://www.docker.com/products/docker-desktop/) ships with everything you need to run Tesseract Core, including the Docker Engine CLI, Docker Compose, and Docker Buildx. It also includes a GUI for managing containers and images.
 It is available for Windows, macOS, and Linux for Debian and Fedora based distros.
 
-If your system is not supported by Docker Desktop, or you prefer a more minimal setup, you will need to install the [`docker` engine CLI](https://docs.docker.com/engine/install/) together with some required plugins:
+If your system is not supported by Docker Desktop, or you prefer a more minimal setup, you will need to install the [`docker` engine CLI](https://docs.docker.com/engine/install/) together with the following plug in:
 
 1. [`docker-buildx`](https://github.com/docker/buildx)
-2. [`docker-compose`](https://github.com/docker/compose)
 
 To use Tesseract without `sudo`, you will need to add your user to the `docker` group. See [Linux post-installation steps for Docker Engine > Manage Docker as a non-root user](https://docs.docker.com/engine/install/linux-postinstall/#manage-docker-as-a-non-root-user), or run:
 
@@ -43,6 +42,16 @@ Then, log out and back in to apply the changes.
 Using `sudo tesseract` may bypass active virtual environments and shadow the `tesseract` command with [conflicting executables](#exe-conflicts). To avoid this, make sure you're using the correct `tesseract` executable, or add your user to the `docker` group (and omit `sudo`).
 ```
 
+(installation-podman)=
+## Using alternative container engines (such as podman)
+
+The choice of container engine can be customised with the environment variable `TESSERACT_DOCKER_EXECUTABLE`. Tesseracts currently support container engines that have API's consistent with the `docker` CLI (e.g. `podman`). Assuming `podman` is already installed on your system and permissions are set up to allow running as a non-root user (typically the default), all that is required is to set the environment variable accordingly.
+
+```bash
+$ export TESSERACT_DOCKER_EXECUTABLE=podman
+$ echo "export TESSERACT_DOCKER_EXECUTABLE=podman" >> ~/.bashrc
+```
+
 (installation-runtime)=
 ## Runtime installation