Added Spanish localization

[Natsume-197]

• Spanish localization added.
• applicationLegalese added to jidoujisho_localisations for both languages available.

Even though there are no dev docs yet, your code is well organized, has comments, and is very understandable. I'm glad you found my pull request earlier helpful and that has made you happy.

[lrorpilla]

Hi, @Natsume-197. Thanks again for contributing.

Several of my users have been Spanish and I know that there is a significant sub community of Spanish immersion learners that have trouble finding and accessing tools that are in English, so I see the need for this.

Given I don't speak Spanish, I can skim for a bit and it checks out from what little I know. I don't have a formal process for verifying and approving this, so I figure I might run these by some people I know for quality assurance. In the event that I might add new text, I would also have to include a Spanish translation for new translation keys, so I am a bit worried (in that event, I might leave those untranslated or get help) but I believe the pros outweigh the cons of having this.

I just want to point out some keys that are untranslated. Is there a reason why they have not been translated?

[lrorpilla]

I'd like to thank you again, I know it has been some effort to even get this partially done, so I am wondering if the undone sections will be amended and updated as part of this PR in the future.

I'd be happy to merge this PR in once I am sure the quality of the translation is good and that all keys are covered.