Fix custom doc link title issue

Author: Kyle-Ye

Sources/SwiftDocC/Model/Rendering/RenderContentCompiler.swift

@@ -163,7 +163,22 @@ struct RenderContentCompiler: MarkupVisitor {
             return [RenderInlineContent.text(link.plainText)]
         }
 
-        return [RenderInlineContent.reference(identifier: .init(resolved.absoluteString), isActive: true, overridingTitle: nil, overridingTitleInlineContent: nil)]
+        let linkTitleInlineContent = link.children.flatMap { visit($0) } as! [RenderInlineContent]
+        let plainTextLinkTitle = linkTitleInlineContent.plainText
+        
+        var overridingTitle = plainTextLinkTitle.isEmpty ? nil : plainTextLinkTitle
+        var overridingTitleInlineContent = linkTitleInlineContent.isEmpty ? nil : linkTitleInlineContent
+        // Check if the link is `<>` form
+        if let linkRange = link.range,
+           let childRange = link.firstChildRange() {
+            let lowerBound = SourceLocation(line: childRange.lowerBound.line, column: childRange.lowerBound.column - 1, source: childRange.lowerBound.source)
+            let upperBound = SourceLocation(line: childRange.upperBound.line, column: childRange.upperBound.column + 1, source: childRange.upperBound.source)
+            if linkRange == lowerBound ..< upperBound {
+                overridingTitle = nil
+                overridingTitleInlineContent = nil
+            }
+        }
+        return [RenderInlineContent.reference(identifier: .init(resolved.absoluteString), isActive: true, overridingTitle: overridingTitle, overridingTitleInlineContent: overridingTitleInlineContent)]
     }
 
     mutating func resolveTopicReference(_ destination: String) -> ResolvedTopicReference? {

Sources/SwiftDocC/Semantics/MarkupReferenceResolver.swift

@@ -113,9 +113,13 @@ struct MarkupReferenceResolver: MarkupRewriter {
         guard let resolvedURL = resolve(reference: unresolved, range: link.range, severity: .warning) else {
             return link
         }
-        var link = link
-        link.destination = resolvedURL.absoluteString
-        return link
+        if link.destination != resolvedURL.absoluteString {
+            var link = link
+            link.destination = resolvedURL.absoluteString
+            return link
+        } else {
+            return link
+        }
     }
 
     mutating func resolveAbsoluteSymbolLink(unresolvedDestination: String, elementRange range: SourceRange?) -> ResolvedTopicReference? {