(*) Rename EdgeDomain$domain into topDomain

This variable had a very confusing name, and was dangerously easy to use in the wrong place with the result of getting something that only works as expected half the time.

Ideally this class needs an overhaul, the assumptions it makes about domain names aren't great.

code/processes/converting-process/src/main/java/nu/marginalia/converting/sideload/stackexchange/StackexchangeSideloader.java

@@ -115,8 +115,9 @@ public class StackexchangeSideloader implements SideloadSource {
             ret.words = keywordExtractor.extractKeywords(dld, url);
             ret.words.addAllSyntheticTerms(List.of(
                     "site:" + domainName,
-                    "site:" + url.domain.domain,
-                    url.domain.domain
+                    "site:" + url.domain.topDomain,
+                    url.domain.topDomain,
+                    domainName
             ));
 
             if (!post.tags().isBlank()) {