fix(bpmn references): proofread and correct

related to #CAM-2375
fix(userguide): proofread and correct

related to #CAM-2329 and #CAM-2326

Conflicts:
	site/src/documents/guides/user-guide/chapters/01-process-engine/03c-inputoutputmapping.html.md
	site/src/documents/guides/user-guide/chapters/01-process-engine/03e-connectors.html.md