doc: Fix old reference to `doc/install` in comment
doc: Fix old reference to `doc/install` in comment

Credit: da39a3ee5e6b4b0d3255bfef95601890afd80709@sheerun
PR-URL: https://github.com/npm/npm/pull/13156
Reviewed-By: da39a3ee5e6b4b0d3255bfef95601890afd80709@zkat

misterbyrne/npm,chadnickbok/npm,evocateur/npm,misterbyrne/npm,DaveEmmerson/npm,evocateur/npm,Volune/npm,chadnickbok/npm,DaveEmmerson/npm,DaveEmmerson/npm,Volune/npm,Volune/npm,evocateur/npm,chadnickbok/npm,misterbyrne/npm