Remove space in image filename and fix markdown and image URLs

[stweil]

Spaces in the names of files or directories are a permanent source of trouble for developers and should therefore be avoided..

Fix also wrong absolute image URLs and buggy markdown titles

[stweil]

Note that index.md contained some more whitespace issues which were automatically fixed by my editor.

[henning-gerhardt]

If I'm not wrong all the documentation inside the repository is moved to the Wiki pages on GitHub and so this documentation is out of date or at least obsolete. I'm correct @solth ?

[solth]

If I'm not wrong all the documentation inside the repository is moved to the Wiki pages on GitHub and so this documentation is out of date or at least obsolete. I'm correct @solth ?

I think you are correct but for once I would like to pass this question to @matthiaskissler, our documentation manager.

[matthiaskissler]

Yes, all documentation was moved to Github Wiki; as to the actuality of the documentation (especially the developer part): it would be nice if this could be tested and, if necessary, updated: https://github.com/kitodo/kitodo-production/wiki/Developer-Documentation-Kitodo.Production-3.x

[stweil]

@matthiaskissler, here it is German user documentation. Is such documentation also available somewhere else? And is it really a good idea to separate user documentation from the code on which it depends? How is the documentation synchronized with code changes then? That's very different to developer documentation.