Add tags

Add tags to allow more granular tasks filtering.
Add generator script for MD formatted tags found.
Add docs for tags how-to.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

roles/docker/tasks/non-systemd.yml

@@ -4,19 +4,23 @@
   set_fact:
     docker_options_file: >-
       {%- if ansible_os_family == "Debian" -%}/etc/default/docker{%- elif ansible_os_family == "RedHat" -%}/etc/sysconfig/docker{%- endif -%}
+  tags: facts
 
 - name: Set docker options config variable name
   set_fact:
     docker_options_name: >-
       {%- if ansible_os_family == "Debian" -%}DOCKER_OPTS{%- elif ansible_os_family == "RedHat" -%}other_args{%- endif -%}
+  tags: facts
 
 - name: Set docker options config value to be written
   set_fact:
     docker_options_value: '"{{ docker_options }} $DOCKER_NETWORK_OPTIONS $DOCKER_STORAGE_OPTIONS $INSECURE_REGISTRY"'
+  tags: facts
 
 - name: Set docker options config line to be written
   set_fact:
     docker_options_line: "{{ docker_options_name }}={{ docker_options_value }}"
+  tags: facts
 
 - name: Set docker proxy lines to be written
   set_fact:
@@ -24,6 +28,7 @@
      - { name: "HTTP_PROXY", value: '"{{ http_proxy }}"' }
      - { name: "HTTPS_PROXY", value: '"{{ https_proxy }}"' }
      - { name: "NO_PROXY", value: '"{{ no_proxy }}"' }
+  tags: facts
 
 - name: Remove docker daemon proxy config lines that don't match desired lines
   lineinfile:
@@ -58,4 +63,4 @@
     mode: 0644
   notify: restart docker
 
-- meta: flush_handlers
+- meta: flush_handlers