notmuch.1: Document the new --entire-thread option to "notmuch show".

This was added to "notmuch help" earlier, but not to the man page.
Add it there, and use consistent wording in both places.

Author: cworth-gh

notmuch.1

@@ -169,6 +169,8 @@ when sorting by
 .B newest\-first
 the threads will be sorted by the newest message in each thread.
 
+.RE
+.RS 4
 By default, results will be displayed in reverse chronological order,
 (that is, the newest results will be displayed first).
 
@@ -177,7 +179,7 @@ See the
 section below for details of the supported syntax for <search-terms>.
 .RE
 .TP
-.BR show " <search-term>..."
+.BR show " [options...] <search-term>..."
 
 Shows all messages matching the search terms.
 
@@ -187,6 +189,19 @@ message in date order). The output is not indented by default, but
 depth tags are printed so that proper indentation can be performed by
 a post-processor (such as the emacs interface to notmuch).
 
+Supported options for
+.B show
+include
+.RS 4
+.TP 4
+.B \-\-entire\-thread
+
+By default only those messages that match the search terms will be
+displayed. With this option, all messages in the same thread as any
+matched message will be displayed.
+.RE
+
+.RS 4
 The  output format  is plain-text,  with all  text-content  MIME parts
 decoded. Various components in the output,
 .RB ( message ", " header ", " body ", " attachment ", and MIME " part ),
@@ -207,6 +222,7 @@ See the
 .B "SEARCH SYNTAX"
 section below for details of the supported syntax for <search-terms>.
 .RE
+.RE
 
 The
 .B reply

notmuch.c

@@ -181,9 +181,10 @@ command_t commands[] = {
       "\n"
       "\t\t--entire-thread\n"
       "\n"
-      "\t\t\tBy default only messages strictly matching the\n"
-      "\t\t\tsearch expression will be displayed.  With this\n"
-      "\t\t\toption all messages in matching threads are shown.\n"
+      "\t\t\tBy default only those messages that match the\n"
+      "\t\t\tsearch terms will be displayed. With this option,\n"
+      "\t\t\tall messages in the same thread as any matched\n"
+      "\t\t\tmessage will be displayed.\n"
       "\n"
       "\t\tThe output format is plain-text, with all text-content\n"
       "\t\tMIME parts decoded. Various components in the output,\n"