initial pageload has "light" set as the theme

[steveklabnik]

Originally found in rust-lang/rust#44704 (comment)

mdbook stores the current theme in localstorage. This changed between 0.0.23 and 0.0.25, with https://github.com/azerupi/mdBook/pull/337 and https://github.com/azerupi/mdBook/pull/324

It basically looks like this:

    var theme = localStorage.getItem('theme');
    if (theme === null) { theme = 'light'; }

However, if you visit a book generated by 0.0.25, and run this in your JS console:

>> localStorage.getItem("theme")
"\"light\""

See the quotes? If you go back to a 0.0.23 generated book, and delete the theme from localstorage, and then refresh, it works, and

>> localStorage.getItem("theme")
"light"

[steveklabnik]

/me sighs

[steveklabnik]

So, one possible solution here is to pick a new key, so that the older mdbooks don't get their theme stuff clobbered. It's not ideal, but at least it works...