* Allows enqueueing by the cli

#372

* schedule support

* `_` to `-`

* fix flake8

* echo job-id

* Some improvements

 - Description as in python jobs
 - return result
 - quiet mode
 - allows `--boolean` and `--integer`
 - raises errors if not used correctly

* added tests

* add schedule tests

* add retry test

* use click exceptions

* add error test

* add job_func test

* change messages

https://github.com/rq/rq/pull/1466#discussion_r640211128
https://github.com/rq/rq/pull/1466#discussion_r640210850

* Use different format for arguments

View https://github.com/rq/rq/pull/1466#discussion_r650510889

* Add file support

Usage: @filename

* ast.literal_eval support with `#` instead of `:`

* func -> function

Makes error messages more readable

* click Error

* print function string

* add docs

* increase seconds in test

* Update `parse_function_arg`

Add `ParsingMode` enum (https://github.com/rq/rq/pull/1466#discussion_r656676114)
Change error messages (https://github.com/rq/rq/pull/1466#discussion_r656676800, https://github.com/rq/rq/pull/1466#discussion_r656677082)

* `#` to `%`

`#` is the letter for a comment in bash

* Add some tests

(https://github.com/rq/rq/pull/1466#discussion_r656674539, https://github.com/rq/rq/pull/1466#discussion_r656676543)

* Add some tests

* docs: Add some examples

* catch all literal_eval exceptions

There are some edge cases with other exceptions

* remove job_func
(https://github.com/rq/rq/pull/1466#pullrequestreview-690110118)

* edit docs

https://github.com/rq/rq/pull/1466#pullrequestreview-695758691

* format examples

* format examples

`queue.enqueue(path.to.func, args=['abc'])` to `queue.enqueue(path.to.func, 'abc')`

https://github.com/rq/rq/pull/1466#discussion_r673615464

* add examples

https://github.com/rq/rq/pull/1466#discussion_r673658933

* add doc test

https://github.com/rq/rq/pull/1466#discussion_r673659124

* Update index.md

* Update test_cli.py

* Update test_cli.py

* Add version info

Co-authored-by: rpkak <rpkak@users.noreply.github.com>