Modify: add cd command
Modify: change math font
Modify: change math font
Merge branch 'feature/mathfont/2-3-1' into develop
Modify: change math font exp()
Modify: change math font of Matrixs
Modify: change math font of vector transpose
Modify: some change
Merge branch 'feature/2-3-6' into develop
Modify: use math font of expected value
Modify: use math font of matrix Sigma
Merge branch 'feature/font/vector' into develop
Modify: use math font of transpose
Merge branch 'feature/font/transpose' into develop
Modify: use math font of Lambda
Merge branch 'feature/font/Lambda' into develop
Modify: use math font of exp()
Modify: use math font of mu
Modify: fix typo of kanji
Modify: add intermediate equation