Removed pull request guidelines
Removed pull request guidelines

Moved to docs repository, check issue [#24]
* Added link to newly moved pull request guidelines in docs repo

exercism/x-common,kgengler/x-common,jmluy/x-common,jmluy/x-common,jmluy/x-common,rpottsoh/x-common,exercism/x-common,petertseng/x-common,Vankog/problem-specifications,petertseng/x-common,Vankog/problem-specifications,kgengler/x-common,ErikSchierboom/x-common,rpottsoh/x-common,ErikSchierboom/x-common