add share icon for bluesky

[geowarin]

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

Adds a share icon for bluesky

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

The social icon was added but not the share button

PR Checklist

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

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[adityatelange]

we cant have a single domain for a decentralised platform. you can't make it customisable because you need to ask user where he/she want to post it.

[geowarin]

Well it is not federated yet (that I know of). Maybe we can start with that and re-evaluate when there are other instances (but I believe most people will stay on the same instance)