Обсуждение: pgsql: Doc: improve documentation about ts_headline() function.

Doc: improve documentation about ts_headline() function.

Now that I've had my nose in that code, I thought the docs about
it left something to be desired.

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/a4d4f59196ea8745fe4c048085d6d2bd66e8e7d8

Modified Files
--------------
doc/src/sgml/textsearch.sgml | 104 ++++++++++++++++++++++++-------------------
1 file changed, 57 insertions(+), 47 deletions(-)