Update docs/faq.md and docs/prerequisites.md: add a note about installing both ansible-core and ansible

See: https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2241#issuecomment-1305361347

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

docs/faq.md

@@ -72,7 +72,7 @@ To get started with the playbook, start at the [Prerequisites](prerequisites.md)
 
 [Ansible](https://www.ansible.com/) is an automation program. This "playbook" is a collection of tasks/scripts that will set up a [Matrix](https://matrix.org/) server for you, so you don't have to perform these tasks manually.
 
-We have written these automated tasks for you and all you need to do is execute them using the Ansible program.
+We have written these automated tasks for you and all you need to do is execute them using the Ansible program. Note that running the playbook requires both `ansible-core` and `ansible`.
 
 You can install Ansible and this playbook code repository on your own computer and tell it to install Matrix services at the server living at `matrix.example.com`. We recommend installing Ansible on your own computer.
 

docs/prerequisites.md

@@ -8,7 +8,7 @@ We will be using `example.com` as the domain in the following instruction. Pleas
 
 ## Your local computer
 
-- [Ansible](http://ansible.com/) program. It's used to run this playbook and configures your server for you. Take a look at [our guide about Ansible](ansible.md) for more information, as well as [version requirements](ansible.md#supported-ansible-versions) and alternative ways to run Ansible.
+- [Ansible](http://ansible.com/) program. It's used to run this playbook and configures your server for you. Take a look at [our guide about Ansible](ansible.md) for more information, as well as [version requirements](ansible.md#supported-ansible-versions) and alternative ways to run Ansible. Note that running the playbook requires both `ansible-core` and `ansible`.
 
 - [passlib](https://passlib.readthedocs.io/en/stable/index.html) Python library. See [this official documentation](https://passlib.readthedocs.io/en/stable/install.html#installation-instructions) for an instruction to install it. On most distros, you need to install some `python-passlib` or `py3-passlib` package, etc.