i-1 Introduces an Ansible playbook for linux-container with SSH access

# Issue

This PR implements the following [issue](the-liberated-edge/test-linux-containers#1).

# Acceptance criteria

- [x] A playbook for launching LXD Debian container with parameterized container name and OS version has been implemented.
- [x] The newly launched Linux containers can be connected to and administered via SSH.
- [x] The playbook has been part of an Ansible collection named theliberatededge.test_linux_containers.
- [x] Setup and getting started technical documentation has been added to README.md.

Co-authored-by: emo <esimeonov@gmail.com>
Reviewed-on: #2

plugins/README.md

@@ -0,0 +1,31 @@
+# Collections Plugins Directory
+
+This directory can be used to ship various plugins inside an Ansible collection. Each plugin is placed in a folder that
+is named after the type of plugin it is in. It can also include the `module_utils` and `modules` directory that
+would contain module utils and modules respectively.
+
+Here is an example directory of the majority of plugins currently supported by Ansible:
+
+```
+└── plugins
+    ├── action
+    ├── become
+    ├── cache
+    ├── callback
+    ├── cliconf
+    ├── connection
+    ├── filter
+    ├── httpapi
+    ├── inventory
+    ├── lookup
+    ├── module_utils
+    ├── modules
+    ├── netconf
+    ├── shell
+    ├── strategy
+    ├── terminal
+    ├── test
+    └── vars
+```
+
+A full list of plugin types can be found at [Working With Plugins](https://docs.ansible.com/ansible-core/2.15/plugins/plugins.html).