Updated documentation.

doc/snac.1

@@ -71,6 +71,10 @@ standalone one.
 If you set this checkbox, your text will not be sent when you
 push the Post button, but stored for later modification in
 the "Drafts" section.
+.It Language
+A dropdown to select which language your post will be written
+in. This control only appears after you configure the set of
+languages you expect to use in the User Settings (see below).
 .It Scheduled post...
 This dropdown menu allows setting a date and time for the
 post publication.
@@ -188,6 +192,9 @@ can be selected here.
 .It Time zone
 The time zone the user is on (default: UTC). Only
 used for scheduled posts.
+.It Languages you usually post in
+Fill this string with the ISO 639 Language Codes you expect to
+write your posts in, space-separated (example: en fr pt_BR).
 .It Password
 Write the same string in these two fields to change your
 password. Don't write anything if you don't want to do this.