What does this PR change? What problem does it solve?

This PR adds the ORCID social icon to the svg.html partial. Having the ORCID social icon may be useful for researchers using ORCID and those using this theme for their Hugo-powered site. The icon used was sourced straight from ORCID's website and official brand assets, particularly the file ORCID-iD_icon_reversed_vector.svg which has been modified to use the theme's currentColor variable for the fill color.

The ORCID social icon in action:

Was the change discussed in an issue or in the Discussions before?

No, this change was not yet raised in an issue or in the Discussions. I was about to create a topic in Discussions but the change seems fairly simple, so I went straight for the PR.

PR Checklist

• This change adds/updates translations and I have used the template present here.
• I have enabled maintainer edits for this PR.
• I have verified that the code works as described/as intended.
• This change adds a Social Icon which has a permissive license to use it.
• This change does not include any CDN resources/links.
• This change does not include any unrelated scripts such as bash and python scripts.
• This change updates the overridden internal templates from HUGO's repository.