Add Spanish and French translations

[madd0]

I noticed translations were recently introduced and wanted to contribute Spanish and French.

I also cleaned up the spacing in existing translations. (Hope it's not a problem, but it's a commit of its own, so can revert.)

Before merging, I have two questions:

• How do you test translations? I tried changing the language of my HA frontend, but didn't notice the translations being used.
• Since I couldn't verify where the translations are used, I have a couple of doubts about some of the entries (masculine vs feminine, noun vs verb, etc.) How about adding some comments to a reference file (either a separate file, or maybe EN?) giving context for translators?

To overcome the fact that JSON doesn't really support comments, I've used workarounds similar to this in other projects:

{
  "key": "value",
  "#key_comment#": "comment for key"
}

Looking forward to your feedback 😄