* Add logout_redirect_url var and option templating for matrix element client

* Simplify logout_redirect_url templating and make it safer

Using `to_json` to make it safer.

Judging by the code here 0b24d33c64/src/Lifecycle.ts (L1026-L1032)
it doesn't seem like it leaving `logout_redirect_url` empty will hurt, so this patch removes the `if` block.

* Add comment for the `matrix_client_element_logout_redirect_url` variable

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Co-authored-by: Slavi Pantaleev <slavi@devture.com>

* Replace "Element" with "Element Web"

- If Element indicates the web application, then it is changed to Element Web.
- If it indicates clients branded with Element such as Element desktop, web, mobile clients, then it is changed to Element clients.
- If it is combined with location sharing functionality, it is not changed.

with other some changes, including:

- Change "app.element.io" anchor link to "https://github.com/element-hq/element-web" on README.md, following other documentation files

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

* Replace "SchildiChat" with "SchildiChat Web"

- If SchildiChat indicates the web application, then it is changed to SchildiChat Web.
- If it indicates clients branded with SchildiChat such as SchildiChat desktop, web, mobile clients, then it is changed to SchildiChat clients.
- If it is combined with location sharing functionality, it is not changed.

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

* Rename configuring-playbook-client-schildichat.md to configuring-playbook-client-schildichat-web.md

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

* Rename configuring-playbook-client-element.md to configuring-playbook-client-element-web.md

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

---------

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

Related to 0241c71a4c

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3270#issuecomment-2143782962

With this change, it should be possible for people to adjust the Docker
dependency from `docker.service` to something else (e.g. `pkg-ContainerManager-dockerd.service`),
or to completely eliminate it by setting `devture_systemd_docker_base_docker_service_name` to an empty string.

This makes it easier for people to use the playbook against a Synology DSM server.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3333

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3288

Ref:
- https://github.com/matrix-org/matrix-react-sdk/pull/12153
- https://github.com/element-hq/element-web/pull/26885

Technically, it may still work for Schildichat, because it's stuck in
the past. It will catch up soon anyway.

Putting each client into its own network was good for isolation,
but it's quite wasteful in terms of the container network pool.