Integrate Spanish translation

[juanjosegzl]

Description

Hola, some time ago I translated the strings to Spanish in transifex.

I wonder what are the next steps to integrate the translation to be released?

I'm open to submit the required changes

Additional context or points of discussion

No response

Validations

• You intend to implement the feature yourself
• You have read the contributing guide
• You strongly believe this feature should be in core, rather than being its own community module
• You have checked for existing issues or pull requests related to this feature (and didn't find any)

[GuySartorelli]

These are pulled through periodically - I think currently it's every 3 months.
The PR for this has just come through. See #844.

We're tracking it internally with silverstripe/.github#234 so I'll close this issue.