office: Rename mail module to office module

Reflecting the somewhat expanding scope of the module, renamed it to
office. Still keeps the old files and setups but also got a new README
file.

office/.config/neomutt/account

@@ -0,0 +1,16 @@
+# Account settings
+# local maildir settings
+set mbox_type = Maildir
+set folder    = ~/documents/mail # This has the shortcut '+' or '='
+set spoolfile = "+inbox"         # This has the shortcut '!'
+set postponed = "+drafts"
+set trash     = "+trash"
+# Disable saving outgoing mail since Gmail saves them by default.
+unset record
+mailboxes   ! \
+            "+important" \
+            "+sent" \
+            "+drafts" \
+            "+trash" \
+            "+archive"
+