Added quick tag and social button functions

【Contents of modification】
■Quick tag function
■Detailed article social button setting function
■Removed unnecessary descriptions in CSS files.

The files that have been modified for this update are as follows
【Added files】
fonts directory
fonts/icomoon.eot
fonts/icomoon.svg
fonts/icomoon.ttf
fonts/icomoon.woff
fonts/common/no_image_card.gif
sns_btn_btm.php
sns_btn_top.php

【Modified files】
admin/theme-options.php
functions.php
languages/en.mo
languages/en.po
single.php
style.css
style_pc.css
style_sp.css

For more information, please visit the download site for purchasers of Opinion (tcd018).