docs: add the contributing guidelines link
docs: add the contributing guidelines link

PR-URL: https://github.com/npm/npm/pull/11441
Credit: da39a3ee5e6b4b0d3255bfef95601890afd80709@watilde
Reviewed-By: da39a3ee5e6b4b0d3255bfef95601890afd80709@iarna

cchamberlain/npm-msys2,chadnickbok/npm,Volune/npm,cchamberlain/npm-msys2,cchamberlain/npm,chadnickbok/npm,DaveEmmerson/npm,lxe/npm,TimeToogo/npm,evocateur/npm,lxe/npm,Volune/npm,cchamberlain/npm,TimeToogo/npm,yodeyer/npm,yodeyer/npm,misterbyrne/npm,evocateur/npm,DaveEmmerson/npm,midniteio/npm,Volune/npm,midniteio/npm,TimeToogo/npm,misterbyrne/npm,cchamberlain/npm,DaveEmmerson/npm,cchamberlain/npm-msys2,yodeyer/npm,lxe/npm,chadnickbok/npm,midniteio/npm,misterbyrne/npm,evocateur/npm