chfn: add page (#2929)

* Create chfn.md

* Update chfn.md

* chfn: tweak grammar

pages/linux/chfn.md

@@ -0,0 +1,19 @@
+# chfn
+
+> Update `finger` info for a user.
+
+- Update a user's "Name" field in the output of `finger`:
+
+`chfn -f {{new_display_name}} {{username}}`
+
+- Update a user's "Office Room Number" field for the output of `finger`:
+
+`chfn -o {{new_office_room_number}} {{username}}`
+
+- Update a user's "Office Phone Number" field for the output of `finger`:
+
+`chfn -p {{new_office_telephone_number}} {{username}}`
+
+- Update a user's "Home Phone Number" field for the output of `finger`:
+
+`chfn -h {{new_home_telephone_number}} {{username}}`