docs: Fix links and formatting

docs: Fix links and formatting

Documentation was updated as follows:
* section decorators were fixed in LTD
* links to testcase and deployment
  descriptions were fixed
* duplicate labels removed from LTP&LTD
* fixed typos in formatting and text
* links to scalability and stress tests
  fixed after their renaming

JIRA: VSPERF-349

Change-Id: I86c2b723231431388b69d3d696805de2a4e12435
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Al Morton <acmorton@att.com>
Reviewed-by: Christian Trautman <ctrautma@redhat.com>
Reviewed-by: Bill Michalowski <bmichalo@redhat.com>