python-markdown: add a new package

[BKPepe]

Maintainer: me
Compile tested: Turris MOX, cortexa53, OpenWrt master
Run tested: Turris MOX, cortexa53, OpenWrt master with example in their documentation

Description:

• add python-markdown

About python3-setuptools dependency:
If I didn't have installed Python3 on the router and when I just installed this package, then it says:

root@turris:~# opkg install python3-markdown_3.1.1-3.7-1_aarch64_cortex-a53.ipk 
Configuring python3-base.
Configuring python3-light.
Configuring python3-markdown.
root@turris:~# python3
Python 3.7.2 (default, Jun 11 2019, 00:02:42) 
[GCC 7.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import markdown
Traceback (most recent call last):
  File "/util.py", line 98, in <module>
ModuleNotFoundError: No module named 'xml.etree.cElementTree'

Then:
AttributeError: module 'logging' has no attribute 'getLogger' as well with ModuleNotFoundError: No module named 'packaging'

Also, setuptools is mention in their setup.py as install_requires.

In any case, I would appreciate when @commodo and @jefferyto will look at it.

[commodo]

this installs setuptools on the target;
i am not sure that is required; it seems required only during build
would removing this also work?

[jefferyto]

It appears to use pkg_resources find extensions, so it does seem to need setuptools installed at run-time. (It also uses it to normalize it's version number.)

[jefferyto]

I would suggest adding python3-logging as a dependency (even though it would be pulled in by python3-setuptools), since you're getting an import error and it does appear to use logging directly.

[BKPepe]

If I don't have any python3 package and install python3-setuptools it installs:
python3-base, python3-light, python3-pydoc, python3-email, python3-cgi, python3-cgitb, python3-decimal, python3-xml, python3-unittest, python3-ncurses, python3-ctypes, python3-multiprocessing- python3-codecs, python3-gdbm, python3- sqlite3, python3-logging, python3-distutils, python3-distutils, python3-openssl, python3-dbm, python3-lzma, python3-asyncio.

So yes, python3-logging it gets pulled by python3-setuptools, but I don't mind to specify there python3-logging as well.