revert: temporary duplicate of contributing guide
revert: temporary duplicate of contributing guide

This reverts commit 1b23a8fc5d5c34ac93b286a6df585c5d5fda9d1b.

jonathanihm/freeCodeCamp,raisedadead/FreeCodeCamp,FreeCodeCamp/FreeCodeCamp,raisedadead/FreeCodeCamp,jonathanihm/freeCodeCamp,FreeCodeCamp/FreeCodeCamp