new icon: datadog (original, original-wordmark)

[canaleal]

Double check these details before you open a PR

• PR does not match another non-stale PR currently opened
• PR name matches the format new icon: Icon name (versions separated by comma). More details here
• PR's base is the develop branch.
• Your icons are inside a folder as seen here
• SVG matches the standards laid out here
• A new object is added in the devicon.json file as seen here

This PR closes #946

Link to prove your SVG is correct and up-to-date.

• Branding

The color #632ca6 was selected for the font SVGs as it's the main color in the original logo.
No line version was created as datadog does not want their icon to be altered in any way.

[github-actions]

Hi!

I'm the check-bot and we have some issues with your PR:

devicon.json is not sorted correctly.
Please make sure that your icon is added in the `devicon.json` file at the correct alphabetic position
as seen here: https://github.com/devicons/devicon/wiki/Updating-%60devicon.json%60

Check our CONTRIBUTING guide for more details regarding these errors.

Please address these issues. When you update this PR, I will check your SVGs again.

Thanks for your help,
SVG-Checker Bot 😄