opt: record xapian total length

website/docs/ui_fulltextsearch.md

@@ -11,7 +11,7 @@ Search modes
 * "Default" — This follows the [xapian search syntax](https://xapian.org/docs/queryparser.html). 
 Note that phrase and NEAR search needs the positional information which may make the Xapian index file impractically large. GoldenDict will heuristically disable positional information when the length of document length reaches a certain limit.
 * "Plain text" - mode like "Whole words" but every word in search line can be treated as word fragment.
-* "Wildcards" - As xapian index only support wildcard syntax like this  "hell*" ,  the wildcard in the middle(eg."he*lo") is not supported.
+* "Wildcards" - support  wildcard syntax like this  "hell*"(As xapian index only support this syntax),  the wildcard in the middle(eg."he*lo") is not supported.
 
 "Available dictionaries in group" - here you can see how many dictionaries in the current group are suitable for full-text search, how many dictionaries are already indexed and how many dictionaries are waiting for indexing.