Add various polish to Conduwuit

https://github.com/Virkkunen and I have been working on the same feature
simultaneously.

This patch adds my additional independent work on top of his changes.

Notable changes here compared to Virkkunen's original work:

- renaming config-related variables (`matrix_conduwuit_*` ->
  `matrix_conduwuit_config_*`). This is consistent with other roles (and
  better), but deviates from how the Conduit role was implemented.

- using a full configuration sample from https://conduwuit.puppyirl.gay/configuration.html
  instead of using the old Conduit config file template

- introducing configurability for more Conduwuit config settings, to support easy registration, etc.

- removing configuration settings that Conduwuit does not support
  anymore (e.g. `max_concurrent_requests`)

- cross-linking docs pages for Conduit and Conduwuit

- a Conduwuit docs page which is much improved compared to the old
  Conduit one

- REAMDE updates

roles/custom/matrix-conduwuit/tasks/uninstall.yml

@@ -0,0 +1,19 @@
+---
+
+- name: Check existence of matrix-conduwuit service
+  ansible.builtin.stat:
+    path: "{{ devture_systemd_docker_base_systemd_path }}/matrix-conduwuit.service"
+  register: matrix_conduwuit_service_stat
+
+- when: matrix_conduwuit_service_stat.stat.exists | bool
+  block:
+    - name: Ensure matrix-conduwuit is stopped
+      ansible.builtin.systemd:
+        name: matrix-conduwuit
+        state: stopped
+        daemon_reload: true
+
+    - name: Ensure matrix-conduwuit.service doesn't exist
+      ansible.builtin.file:
+        path: "{{ devture_systemd_docker_base_systemd_path }}/matrix-conduwuit.service"
+        state: absent