added some missing resource files in spanish

[adocampo]

I'm facing a problem in this code:

    "date_time_format": {
    "date_time": "{formatted_date} at {formatted_time}"
  },

In spanish, when we said 1am or 1pm (01h or 13h) we say la una, the other 23 hours we say las X (e.g: las dos, las diez, etc)... how could I translate this?
I could use 24h format, and let it as

    "date_time_format": {
    "date_time": "{formatted_date} a las {formatted_time}"
  },

but this would leave the case of 01h, which needs to be {formatted_date} a la {formatted_time}

[JarbasAl]

i a having the same problem, for now i just left it in the plural form

i plan on doing some refactor to that class, in particular i want to make it use the pronounce_number methods, take a look at the portuguese PR for an early version

we can make another PR later on handling these edge cases