Splitting occ_command.rst into two files for core and apps

[mmattel]

This PR splits the current occ_command.rst into two files:

occ_command.rst core related
and
occ_apps_command.rst apps related

occ_command.rst contains all commands for the core system.

occ_apps_command.rst contains now all commands for apps provided by ownCloud.
I went thru all repros and added all commands I have identified and described on best effort.

owncloud/core#32387 (Splitting config.sample.php into two files for core and app)

@settermjd please let me know or pls do by yourself how to add the new file into the doc structure to make it visible.

ToDo: Harmonize the layout to tables. Should be done in a seperate PR

FYI @PVince81 @DeepDiver1975 @patrickjahns @phil-davis

[settermjd]

Thanks @mmattel

[mmattel]

@settermjd info

I have added and improved in the meanwhile a lot of content in the new occ_apps_command.rst file.
If you watch via restview you will see how professional this looks now 😃
This is the way of UI changes I would like to see in occ_command.rst file too (to be made in seperate PR´s)

[settermjd]

This all looks good to me. But it still needs to be linked into a table of contents before it can be approved.

[mmattel]

The changes you have made for the occ_apps_command.rst description on top (before the commands are described), could you do those changes in occ_command.rst too so we have that in sync ?

Update: obsolete, I added some general text and synced the files

[settermjd]

Thanks for all the hard work on this one.