Disable @typescript-eslint/no-extra-semi

[xcatliu]

The new rule @typescript-eslint/no-extra-semi has been added since @typescript-eslint/eslint-plugin@2.13.0.

• https://github.com/typescript-eslint/typescript-eslint/blob/v2.13.0/packages/eslint-plugin/docs/rules/no-extra-semi.md
• https://github.com/typescript-eslint/typescript-eslint/releases/tag/v2.13.0
• feat(eslint-plugin): add no-extra-semi [extension] typescript-eslint/typescript-eslint#1237

This rule is an extension of the ESLint core rule no-extra-semi,
and eslint-config-prettier has disabled the rule already.

• eslint-config-prettier/index.js

  Line 52 in dcca556

  "no-extra-semi": "off",

[xcatliu]

#128