Add/improve various symbols (#933)

* Expand shogi symbols

* Add Mahjong symbols

* Improve arrows

* Improve superscript/subscript

* Add bidakuon kana

* Add/fix dash

* Improve pairs of parenthesis/quotations

* Add/improve math/unit symbols

* Add pronunciation symbols

PiperOrigin-RevId: 638198725

Author: tats-u