入力補完に＃と＠を追加

[Npepperlinux]

ノートの入力補完に#と@を追加する提案です。
（displayTextも追加しましたが、使っていないように見えます。）

[codecov-commenter]

Codecov Report

Merging #423 (351855c) into develop (f6e7bfb) will increase coverage by 0.03%.
Report is 1 commits behind head on develop.
The diff coverage is 100.00%.

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@@             Coverage Diff             @@
##           develop     #423      +/-   ##
===========================================
+ Coverage    26.95%   26.99%   +0.03%     
===========================================
  Files          235      235              
  Lines        11403    11409       +6     
===========================================
+ Hits          3074     3080       +6     
  Misses        8329     8329              

Files	Coverage Δ
lib/view/common/note_create/basic_keyboard.dart	100.00% <100.00%> (ø)

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[shiosyakeyakini-info]

マージしました！ありがとうございます！