Shares the chosen theme with every component. ThemeProvider fills this
context and useTheme reads it.
I
ThemeContextValue
Provided by ThemeProvider to useTheme. A setter applies the choice and
stores it in this browser, and in the account's settings when signed in.
v
ThemeContext: React.Context<ThemeContextValue>
The theme's context. Its default is only seen outside ThemeProvider.
Usage
import * as mod from "src/contexts/theme/ThemeContext.ts";