pgsql: Doc: Improve description of connection strings with Percent-enco

Doc: Improve description of connection strings with Percent-encoding

Clarify the description related to the use of characters which can be
encoded, and add an example.

Author: Jobin Augustine
Reviewed-by: Peter Eisentraut, Alvaro Herrera, Heikki Linnakangas,
Michael Paquier, Alex Shulgin
Discussion: https://postgr.es/m/CANaTPsrYgSgE2fuj3=4x=Jmx1c+NgkEDzftNknZbrMuqL+aBhQ@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/e0ed6817c0ee218a3681920807404603e042ff04

Modified Files
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doc/src/sgml/libpq.sgml | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)