##### SUMMARY
The warning that `become` show, point to a non-existing page.

The reference: https://docs.ansible.com/ansible/become.html#becoming-an-unprivileged-user
Should be: https://docs.ansible.com/ansible/user_guide/become.html#risks-of-becoming-an-unprivileged-user

```
  msg: |-
    Failed to set permissions on the temporary files Ansible needs to create when becoming an unprivileged user (rc: 1, err: chown: changing ownership of '/var/tmp/ansible-tmp-1587201990.1515293-106086999273646/': Operation not permitted
    chown: changing ownership of '/var/tmp/ansible-tmp-1587201990.1515293-106086999273646/AnsiballZ_postgresql_db.py': Operation not permitted
    }). For information on working around this, see https://docs.ansible.com/ansible/become.html#becoming-an-unprivileged-user
```

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
become

##### ANSIBLE VERSION
```
ansible 2.9.6
  config file = None
  configured module search path = ['/home/robertdb/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.7/site-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 3.7.6 (default, Jan 30 2020, 09:44:41) [GCC 9.2.1 20190827 (Red Hat 9.2.1-1)]
```

##### CONFIGURATION
```
# empty.
```

##### OS / ENVIRONMENT
Controller: Fedora 31
Managed node: Ubuntu 19

##### STEPS TO REPRODUCE
I use [this](https://github.com/robertdebock/ansible-role-postgres/blob/master/tasks/main.yml#L70) role on Ubuntu 19. (Using [this](https://github.com/robertdebock/ansible-tester) code.

##### EXPECTED RESULTS
The chapter is found immediately.

##### ACTUAL RESULTS
The documentation page loads (good), but does not jump to the right chapter.
may be commands to create/remove directories for temporary files, or to
        run the module code or python directly when pipelining.
        :kwarg encoding_errors: If the value returned by the command isn't
            utf-8 then we have to figure out how to transform it to unicode.
            If the value is just going to be displayed to the user (or
            discarded) then the default of 'replace' is fine.  If the data is
            used as a key or is going to be written back out to a file
            verbatim, then this won't work.  May have to use some sort of
            replacement strategy (python3 could use surrogateescape)
        :kwarg chdir: cd into this directory before executing the command.
        '''
        display.debug("_low_level_execute_command(): starting")
        
        
        
        
        if chdir:
            display.debug("_low_level_execute_command(): changing cwd to %s for this command" % chdir)
            cmd = self._connection._shell.append_command('cd %s' % chdir, cmd)
        ruser = self._get_remote_user()
        buser = self.get_become_option('become_user')
        if (sudoable and self._connection.become and  
                self._connection.transport.split('.')[-1] != 'network_cli' and  
                (C.BECOME_ALLOW_SAME_USER or (buser != ruser or not any((ruser, buser))))):  
            display.debug("_low_level_execute_command(): using become for this command")
            cmd = self._connection.become.build_become_command(cmd, self._connection._shell)
        if self._connection.allow_executable:
            if executable is None:
                executable = self._play_context.executable