Merge branch 'toc-equal-page-headings' into 'preview'

Adopt page heading to TOC

See merge request !815

doc.zih.tu-dresden.de/docs/data_transfer/datamover.md

-# Datamover - Data Transfer Inside ZIH Systems
+# Transfer Data Inside ZIH Systems with Datamover
 
 With the **Datamover**, we provide a special data transfer machine for transferring data with best
 transfer speed between the filesystems of ZIH systems. The Datamover machine is not accessible

doc.zih.tu-dresden.de/docs/data_transfer/export_nodes.md

-# Export Nodes - Data Transfer to/from ZIH Systems
+# Transfer Data to/from ZIH Systems via Export Nodes
 
 To copy large data to/from ZIH systems, the so-called **export nodes** should be used. While it is
 possible to transfer small files directly via the login nodes, they are not intended to be used that