[INTERNAL][FIX] Markdown syntax correction in guidelines doc
[INTERNAL][FIX] Markdown syntax correction in guidelines doc

Closes: https://github.com/SAP/openui5/pull/1506
Change-Id: I04be3e5157a616db4a3b8dab2c912adab4c4604b

SQCLabs/openui5,SAP/openui5,SQCLabs/openui5,cschuff/openui5,nzamani/openui5,nzamani/openui5,cschuff/openui5,SAP/openui5,SAP/openui5,nzamani/openui5,cschuff/openui5,SQCLabs/openui5,SAP/openui5