$ cat test.yml
---
- hosts: all
  tasks:
    - shell: ls -d */ | cut -d '/' -f 1 chdir=/
      register: directories_output
    - set_fact: directories="{{ directories_output.stdout_lines }}"
    - debug: var=directories_output.stdout_lines
    - debug: var=directories
    - template: src="templates/conf.j2" dest="/tmp/conf"

$ cat templates/conf.j2
{% for directory in directories %}
{{ directory }}
{% endfor %}

$ ansible-playbook test.yml
PLAY [all] ********************************************************************

GATHERING FACTS ***************************************************************
ok: [slvm3]

TASK: [shell ls -d */ | cut -d '/' -f 1 chdir=/] ******************************
changed: [slvm3]

TASK: [set_fact directories="{{ directories_output.stdout_lines }}"] **********
ok: [slvm3]

TASK: [debug var=directories_output.stdout_lines] *****************************
ok: [slvm3] => {
    "directories_output.stdout_lines": [
        "bin",
        "boot",
        "dev",
        "etc",
        "home",
        "lib",
        "lib64",
        "lost+found",
        "media",
        "mnt",
        "opt",
        "proc",
        "root",
        "sbin",
        "selinux",
        "srv",
        "sys",
        "tmp",
        "usr",
        "vagrant",
        "var"
    ]
}

TASK: [debug var=directories] *************************************************
ok: [slvm3] => {
    "directories": [
        "bin",
        "boot",
        "dev",
        "etc",
        "home",
        "lib",
        "lib64",
        "lost+found",
        "media",
        "mnt",
        "opt",
        "proc",
        "root",
        "sbin",
        "selinux",
        "srv",
        "sys",
        "tmp",
        "usr",
        "vagrant",
        "var"
    ]
}

TASK: [template src="templates/conf.j2" dest="/tmp/conf"] *********************
changed: [slvm3]

PLAY RECAP ********************************************************************
slvm3                      : ok=6    changed=2    unreachable=0    failed=0


$ cat /tmp/conf
[
u
'
b
i
n
'
,

u
'
b
o
o
t
'
,

u
'
d
e
v
'
,

...