Question: How to import multiple types from another file
I wen through the documentation and it has provided how you can import a type from a different file. (for single type this is fine and we may have to have a file for each type with this, I've also noted that web IDE tool cannot have imports and correct me if I'm wrong)

What I want is group certain types which are related to certain records type into one file and then import that file to refer the types defined in that. How do you do that

ex: say I have a `main.ksy` as below

~~~yml
meta:
  id: event_x500
  endian: be
  imports:
    - file_header
    - chr_header

seq:
  - id: file_header
    type: t_file_header # this is from `file_header` import
  - id: chr_header
    type: t_chr_header # this is from `chr_header` import
    repeat: eos

types:
  ...
  ...
~~~

`file_header.ksy`

~~~yml
meta:
  id: t_file_header
  endian: be
seq:
  - id: main_version
    type: u1
  - id: sub_version
    type: u1
~~~

`chr_header.ksy`

~~~yml
meta:
  id: t_chr_header
  endian: be
seq:
  - id: event_id
    type: u2
  - id: event_length
    type: u4
~~~

Now the question is how can I put both `t_chr_header` and `t_file_header` into single file and import it. Can't we have `types` section without `seq`, which I tried but didn't work

ex: something like this

`common_headers.ksy`

~~~yml
meta:
  id: common_headers
  endian: be
types:
  t_chr_header:
   seq:
     - id: event_id
       type: u2
     - id: event_length
       type: u4 

  t_file_header:
    seq:
      - id: main_version
        type: u1
      - id: sub_version
        type: u1  
~~~

and then in `main.ksy`

~~~yml
meta:
  id: event_x500
  endian: be
  imports:
    - common_headers

seq:
  - id: file_header
    type: t_file_header # this is from `common_headers` import
  - id: chr_header
    type: t_chr_header # this is from `common_headers` import
    repeat: eos
~~~
