pythagorean-triplet: Describe problem with variable sum N (#1395)
pythagorean-triplet: Describe problem with variable sum N (#1395)

This form of the problem was ratified in the canonical data
https://github.com/exercism/problem-specifications/pull/1332

Closes https://github.com/exercism/problem-specifications/issues/1211
exercism/x-common,rpottsoh/x-common,petertseng/x-common,ErikSchierboom/x-common,jmluy/x-common,jmluy/x-common,rpottsoh/x-common,petertseng/x-common,ErikSchierboom/x-common,exercism/x-common,jmluy/x-common