environ.7: Note that child of fork(2) inherits copy of parent's environment

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man7/environ.7

@@ -53,6 +53,11 @@ feature test macro is defined.)
 This array of strings is made available to the process by the
 .BR exec (3)
 call that started the process.
+When a child process is created via
+.BR fork (2),
+it inherits a
+.I copy
+of its parent's environment.
 
 By convention the strings in
 .I environ