README.md: Remove TODO about integrating with DSpace

I have now published the code on https://oss.sonatype.org/ via the
Sonatype OSSRH (OSS Repository Hosting) project. Now it is possible
to use it from DSpace's build system by adding it as a dependency
in the dspace/modules/additions/pom.xml.

See: https://issues.sonatype.org/browse/OSSRH-59650
See: https://central.sonatype.org/pages/ossrh-guide.html

README.md

@@ -36,7 +36,6 @@ $ mvn -B archetype:generate -DgroupId=io.github.ilri.cgspace -DartifactId=dspace
 
 ## Todo
 
-- Integrate with main DSpace build
 - Make sure this doesn't work on items in the workflow
 - Port to DSpace 6
   - Remember to bump Gson version!