chsh, chpass: add pages; pages/linux/chsh: update page (#12160)

* chpass, chsh: add page for {Free,Net,Open}BSD and update common page

* pages.*BSD: add aliases for chpass

* chpass: add page for osx

pages/freebsd/chpass.md

@@ -0,0 +1,33 @@
+# chpass
+
+> Add or change user database information, including login shell and password.
+> See also: `passwd`.
+> More information: <https://man.freebsd.org/cgi/man.cgi?chpass>.
+
+- Add or change user database information for the current user interactively:
+
+`su -c chpass`
+
+- Set a specific login [s]hell for the current user:
+
+`chpass -s {{path/to/shell}}`
+
+- Set a login [s]hell for a specific user:
+
+`chpass -s {{path/to/shell}} {{username}}`
+
+- Change the account [e]xpire time (in seconds from the epoch, UTC):
+
+`su -c 'chpass -e {{time}} {{username}}'`
+
+- Change a user's password:
+
+`su -c 'chpass -p {{encrypted_password}} {{username}}'`
+
+- Specify the [h]ostname or address of an NIS server to query:
+
+`su -c 'chpass -h {{hostname}} {{username}}'`
+
+- Specify a particular NIS [d]omain (system domain name by default):
+
+`su -c 'chpass -d {{domain}} {{username}}'`