##### SUMMARY
The [`with_sequence` documentation](https://docs.ansible.com/ansible/latest/plugins/lookup/sequence.html) does not have enough examples to clarify.

The "Edit on GitHub" link is also broken, so it's hard to fix.

1. How to use non-inline variables:
How do you write this:
```yaml
- name: Example
  debug:
    msg: "{{ item }}"
  with_sequence: start=1 end=10
```

Like this?:
```yaml
- name: Example
  debug:
    msg: "{{ item }}"
  with_sequence:
    start: 1
    end: 10
```
(The second example doesn't actually work. What is the correct syntax without using one-liner equals statements?)

2. Show an example like this:
```yaml
- name: Example
  debug:
    msg: "{{ item }}"
  with_sequence: start=1 end="{{ number_of_things }}"
```
(It references a variable for the `end` parameter.)

##### ISSUE TYPE
- Documentation Report

##### COMPONENT NAME
sequence
if self.count is None and self.end is None:
            raise AnsibleError("must specify count or end in with_sequence")
        elif self.count is not None and self.end is not None:
            raise AnsibleError("can't specify both count and end in with_sequence")
        elif self.count is not None:
            
            if self.count != 0:
                self.end = self.start + self.count * self.stride - 1
            else:
                self.start = 0
                self.end = 0
                self.stride = 0
            del self.count
        if self.stride > 0 and self.end < self.start:
            raise AnsibleError("to count backwards make stride negative")
        if self.stride < 0 and self.end > self.start:
            raise AnsibleError("to count forward don't make stride negative")
        if self.format.count('%') != 1:
            raise AnsibleError("bad formatting string: %s" % self.format)
    def generate_sequence(self):