new icon: chartjs (original, original-wordmark, plain, plain-wordmark)

[weh]

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

closes #1822

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

https://www.chartjs.org/

[canaleal]

Nice, thank you for the contribution.
Just optimized and combined the plain svg paths.

[weh]

optimized with correct svgomg options this time, and rebased to current develop branch

[canaleal]

Great stuff. LGTM

[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



SVG Error in 'chartjs-plain.svg':
- SVG contains `stroke` property. This will get ignored by Icomoon. Please convert them to fills.

SVG Error in 'chartjs-plain-wordmark.svg':
- SVG contains `stroke` property. This will get ignored by Icomoon. Please convert them to fills.

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 😄

[canaleal]

Excellent work.