[source-request] add mangadex as source

[acofmelt]

Since batoto closed this new site has been gaining popularity due to being a similar concept, would be nice to have it as a source.

[aplanas]

Sure thing.

[aplanas]

MangaDex is added here:

185819f

[Lswhiteh]

Not getting mangadex results in most searches, but on the few occasions I've got them it says they're disabled.

[aplanas]

Yeah, sorry, I still have the IP limit issue:

https://mangadex.org/thread/12869/too-many-hits-detected-from-your-ip

[Lswhiteh]

Don't apologize! Just wanted to point it out. Your app is great, thank you! I hope that they eventually lift the limit a little for apps like yours.