##### SUMMARY
<!--- Explain the problem briefly below, add suggestions to wording or structure -->
The [main configuration documentation](https://docs.ansible.com/ansible/latest/reference_appendices/config.html#ansible-pipelining) says that pipelining is enabled in the `ssh_connection` or `connection` section.

The [ssh connection plugin](https://docs.ansible.com/ansible/latest/plugins/connection/ssh.html#parameter-pipelining) configuration says pipelining should  be enabled in the `defaults` section.

#31125 (and the associated commit) seems to imply that the `ssh_connection` section is legacy, but the comments (https://github.com/ansible/ansible/issues/31125#issuecomment-334071699) seem to say otherwise.

The actual sections (as demonstrated in the configuration section below) that works are `ssh_connection` and `connection`.


##### ISSUE TYPE
- Documentation Report

##### COMPONENT NAME
ssh

##### ANSIBLE VERSION

```paste below
ansible 2.9.9
  config file = /c/xxx/ansible/ansible.cfg
  configured module search path = ['/c/Users/bendem/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /c/Users/bendem/.local/share/virtualenvs/ansible-oaopcvR0/lib/python3.8/site-packages/ansible
  executable location = /c/Users/bendem/.local/share/virtualenvs/ansible-oaopcvR0/bin/ansible
  python version = 3.8.3 (default, May 18 2020, 08:39:23) [GCC 9.3.0]
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
With `[defaults]\npipelining = true`

```
ALLOW_WORLD_READABLE_TMPFILES(/c/xxx/ansible/ansible.cfg) = False
ANSIBLE_SSH_EXECUTABLE(/c/xxx/ansible/ansible.cfg) = /usr/bin/ssh
ANSIBLE_SSH_RETRIES(/c/xxx/ansible/ansible.cfg) = 1
DEFAULT_HOST_LIST(/c/xxx/ansible/ansible.cfg) = ['/c/xxx/ansible/inventory/inventory.ini']
DEFAULT_ROLES_PATH(/c/xxx/ansible/ansible.cfg) = ['/c/xxx/ansible/vendors/roles', '/c/xxx/ansible/roles']
DEFAULT_VAULT_ID_MATCH(/c/xxx/ansible/ansible.cfg) = true
DIFF_ALWAYS(/c/xxx/ansible/ansible.cfg) = True
INTERPRETER_PYTHON(/c/xxx/ansible/ansible.cfg) = /usr/bin/python3
INVENTORY_UNPARSED_IS_FAILED(/c/xxx/ansible/ansible.cfg) = True
```

With `[ssh_connection]\npipelining = true`

```paste below
ALLOW_WORLD_READABLE_TMPFILES(/c/xxx/ansible/ansible.cfg) = False
ANSIBLE_PIPELINING(/c/xxx/ansible/ansible.cfg) = True
ANSIBLE_SSH_EXECUTABLE(/c/xxx/ansible/ansible.cfg) = /usr/bin/ssh
ANSIBLE_SSH_RETRIES(/c/xxx/ansible/ansible.cfg) = 1
DEFAULT_HOST_LIST(/c/xxx/ansible/ansible.cfg) = ['/c/xxx/ansible/inventory/inventory.ini']
DEFAULT_ROLES_PATH(/c/xxx/ansible/ansible.cfg) = ['/c/xxx/ansible/vendors/roles', '/c/xxx/ansible/roles']
DEFAULT_VAULT_ID_MATCH(/c/xxx/ansible/ansible.cfg) = true
DIFF_ALWAYS(/c/xxx/ansible/ansible.cfg) = True
INTERPRETER_PYTHON(/c/xxx/ansible/ansible.cfg) = /usr/bin/python3
INVENTORY_UNPARSED_IS_FAILED(/c/xxx/ansible/ansible.cfg) = True
```

With `[connection]\npipelining = true`

```paste below
ALLOW_WORLD_READABLE_TMPFILES(/c/xxx/ansible/ansible.cfg) = False
ANSIBLE_PIPELINING(/c/xxx/ansible/ansible.cfg) = True
ANSIBLE_SSH_EXECUTABLE(/c/xxx/ansible/ansible.cfg) = /usr/bin/ssh
ANSIBLE_SSH_RETRIES(/c/xxx/ansible/ansible.cfg) = 1
DEFAULT_HOST_LIST(/c/xxx/ansible/ansible.cfg) = ['/c/xxx/ansible/inventory/inventory.ini']
DEFAULT_ROLES_PATH(/c/xxx/ansible/ansible.cfg) = ['/c/xxx/ansible/vendors/roles', '/c/xxx/ansible/roles']
DEFAULT_VAULT_ID_MATCH(/c/xxx/ansible/ansible.cfg) = true
DIFF_ALWAYS(/c/xxx/ansible/ansible.cfg) = True
INTERPRETER_PYTHON(/c/xxx/ansible/ansible.cfg) = /usr/bin/python3
INVENTORY_UNPARSED_IS_FAILED(/c/xxx/ansible/ansible.cfg) = True
```

##### OS / ENVIRONMENT
Windows 10, msys2 python3, not that it matters.

##### ADDITIONAL INFORMATION
<!--- Describe how this improves the documentation, e.g. before/after situation or screenshots -->

<!--- HINT: You can paste gist.github.com links for larger files -->

'''
        Takes a command array and scans it for ControlPersist and ControlPath
        settings and returns two booleans indicating whether either was found.
        This could be smarter, e.g. returning false if ControlPersist is 'no',
        but for now we do it simple way.
        '''
        controlpersist = False
        controlpath = False
        for b_arg in (a.lower() for a in b_command):
            if b'controlpersist' in b_arg:
                controlpersist = True
            elif b'controlpath' in b_arg:
                controlpath = True
        return controlpersist, controlpath
    def _add_args(self, b_command, b_args, explanation):
        """
        Adds arguments to the ssh command and displays a caller-supplied explanation of why.
        :arg b_command: A list containing the command to add the new arguments to.
            This list will be modified by this method.
        :arg b_args: An iterable of new arguments to add.  This iterable is used
            more than once so it must be persistent (ie: a list is okay but a
            StringIO would not)
        :arg explanation: A text string containing explaining why the arguments
            were added.  It will be displayed with a high enough verbosity.
        .. note:: This function does its work via side-effect.  The b_command list has the new arguments appended.
        """
        display.vvvvv(u'SSH: %s: (%s)' % (explanation, ')('.join(to_text(a) for a in b_args)), host=self._play_context.remote_addr)
        b_command += b_args
    def _build_command(self, binary, *other_args):