Move roles/matrix* to roles/custom/matrix*

This paves the way for installing other roles into `roles/galaxy` using `ansible-galaxy`,
similar to how it's done in:

- https://github.com/spantaleev/gitea-docker-ansible-deploy
- https://github.com/spantaleev/nextcloud-docker-ansible-deploy

In the near future, we'll be removing a lot of the shared role code from here
and using upstream roles for it. Some of the core `matrix-*` roles have
already been extracted out into other reusable roles:

- https://github.com/devture/com.devture.ansible.role.postgres
- https://github.com/devture/com.devture.ansible.role.systemd_docker_base
- https://github.com/devture/com.devture.ansible.role.timesync
- https://github.com/devture/com.devture.ansible.role.vars_preserver
- https://github.com/devture/com.devture.ansible.role.playbook_runtime_messages
- https://github.com/devture/com.devture.ansible.role.playbook_help

We just need to migrate to those.

roles/custom/matrix-base/tasks/setup_well_known.yml

@@ -0,0 +1,52 @@
+---
+# We need others to be able to read these directories too,
+# so that matrix-nginx-proxy's nginx user can access the files.
+#
+# For running with another webserver, we recommend being part of the `matrix` group.
+- name: Ensure Matrix static-files path exists
+  ansible.builtin.file:
+    path: "{{ item }}"
+    state: directory
+    mode: 0755
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  with_items:
+    - "{{ matrix_static_files_base_path }}/.well-known/matrix"
+
+- name: Ensure Matrix /.well-known/matrix/client file configured
+  ansible.builtin.copy:
+    content: "{{ matrix_well_known_matrix_client_configuration | to_nice_json }}"
+    dest: "{{ matrix_static_files_base_path }}/.well-known/matrix/client"
+    mode: 0644
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+
+- name: Ensure Matrix /.well-known/matrix/server file configured
+  ansible.builtin.copy:
+    content: "{{ matrix_well_known_matrix_server_configuration | to_nice_json }}"
+    dest: "{{ matrix_static_files_base_path }}/.well-known/matrix/server"
+    mode: 0644
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  when: matrix_well_known_matrix_server_enabled | bool
+
+- name: Ensure Matrix /.well-known/matrix/server file deleted
+  ansible.builtin.file:
+    path: "{{ matrix_static_files_base_path }}/.well-known/matrix/server"
+    state: absent
+  when: "not matrix_well_known_matrix_server_enabled | bool"
+
+- name: Ensure Matrix /.well-known/matrix/support file configured
+  ansible.builtin.copy:
+    content: "{{ matrix_well_known_matrix_support_configuration | to_nice_json }}"
+    dest: "{{ matrix_static_files_base_path }}/.well-known/matrix/support"
+    mode: 0644
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  when: matrix_well_known_matrix_support_enabled | bool
+
+- name: Ensure Matrix /.well-known/matrix/support file deleted
+  ansible.builtin.file:
+    path: "{{ matrix_static_files_base_path }}/.well-known/matrix/support"
+    state: absent
+  when: "not matrix_well_known_matrix_support_enabled | bool"