add hide on start option (#1919)

* add hide on start option (#1918)

* text update

* clean up

* removed `hideOnStart` from ConfigV1 & ConfigV2

* tests update

src/main/Validator.ts

@@ -119,6 +119,7 @@ const configDataSchemaV3 = Joi.object<ConfigV3>({
     useSpellChecker: Joi.boolean().default(true),
     enableHardwareAcceleration: Joi.boolean().default(true),
     autostart: Joi.boolean().default(true),
+    hideOnStart: Joi.boolean().default(false),
     spellCheckerLocales: Joi.array().items(Joi.string()).default([]),
     spellCheckerURL: Joi.string().allow(null),
     darkMode: Joi.boolean().default(false),