[Website] Update repositories that did not have GitHub discussions (#640)

The repositories that did not have GitHub discussions have been updated
to also have GitHub discussions enabled.
This PR updates the links and some minor details on the wording to
remove the conditional.

See:
- apache/arrow-java#710
- apache/arrow-julia#546
- apache/arrow-go#353

Author: raulcd

community.md

@@ -90,14 +90,15 @@ activity is captured in email form for archival purposes.
 
 ### GitHub
 
-<p>We use GitHub Issues as a place to report bugs, request new features, and track the queue of development work. For usage questions, some of our repositories use GitHub Discussions as an alternative to the <code>user@</code> mailing list {% include mailing_list_links.html list="user" %}. For those repositories, Discussions are mirrored to the <code>user@</code> mailing list {% include mailing_list_links.html list="user" %} and users are welcome to ask usage questions in either location. Maintainers may convert usage type Issues to Discussions as appropriate.</p>
+<p>We use GitHub Issues as a place to report bugs, request new features, and track the queue of development work. For usage questions, our repositories use GitHub Discussions as an alternative to the <code>user@</code> mailing list {% include mailing_list_links.html list="user" %}. Discussions are mirrored to the <code>user@</code> mailing list {% include mailing_list_links.html list="user" %} and users are welcome to ask usage questions in either location. Maintainers may convert usage type Issues to Discussions as appropriate.</p>
 
 Please create Issues or start Discussions on the appropriate repository:
 
 Implementations:
 
-- Go: [apache/arrow-go](http://github.com/apache/arrow-go) ([Issues](http://github.com/apache/arrow-go/issues))
-- Java: [apache/arrow-java](http://github.com/apache/arrow-java) ([Issues](http://github.com/apache/arrow-java/issues))
+- Go: [apache/arrow-go](http://github.com/apache/arrow-go) ([Issues](http://github.com/apache/arrow-go/issues), [Discussions](https://github.com/apache/arrow-go/discussions))
+- Java: [apache/arrow-java](http://github.com/apache/arrow-java) ([Issues](http://github.com/apache/arrow-java/issues), [Discussions](https://github.com/apache/arrow-java/discussions))
+- Julia: [apache/arrow-julia](http://github.com/apache/arrow-julia) ([Issues](http://github.com/apache/arrow-julia/issues), [Discussions](https://github.com/apache/arrow-julia/discussions))
 - nanoarrow: [apache/arrow-nanoarrow](https://github.com/apache/arrow-nanoarrow) ([Issues](https://github.com/apache/arrow-nanoarrow/issues), [Discussions](https://github.com/apache/arrow-nanoarrow/discussions))
 - Rust: [apache/arrow-rs](http://github.com/apache/arrow-rs) ([Issues](http://github.com/apache/arrow-rs/issues), [Discussions](http://github.com/apache/arrow-rs/discussions))
 - .NET: [apache/arrow-dotnet](https://github.com/apache/arrow-dotnet) ([Issues](https://github.com/apache/arrow-dotnet/issues), [Discussions](https://github.com/apache/arrow-dotnet/discussions))