Use unicode literals to clarify that 3 different characters are added to the set

Author: d-ronnqvist

Sources/DocCHTML/MarkdownRenderer.swift

@@ -844,7 +844,7 @@ private extension CharacterSet {
         .union(CharacterSet(charactersIn: "`"))       // Also consider back-ticks as punctuation. They are used as quotes around symbols or other code.
         .subtracting(CharacterSet(charactersIn: "-")) // Don't remove hyphens. They are used as a whitespace replacement.
     static let whitespaceAndDashes = CharacterSet.whitespaces
-        .union(CharacterSet(charactersIn: "-–—")) // hyphen, en dash, em dash
+        .union(CharacterSet(charactersIn: "-\u{2013}\u{2014}")) // hyphen, en dash, em dash
 }
 
 /// Creates a more readable version of a fragment by replacing characters that are not allowed in the fragment of a URL with hyphens.

Sources/SwiftDocC/Infrastructure/Link Resolution/PathHierarchyBasedLinkResolver.swift

@@ -337,7 +337,7 @@ private func linkName(filename: some StringProtocol) -> String {
 }
 
 private let whitespaceAndDashes = CharacterSet.whitespaces
-    .union(CharacterSet(charactersIn: "-–—")) // hyphen, en dash, em dash
+    .union(CharacterSet(charactersIn: "-\u{2013}\u{2014}")) // hyphen, en dash, em dash
 
 private extension PathHierarchy.Node {
     func matches(languagesFilter: SmallSourceLanguageSet) -> Bool {

Sources/SwiftDocC/Model/Identifier.swift

@@ -642,7 +642,7 @@ private extension CharacterSet {
         .union(CharacterSet(charactersIn: "`"))       // Also consider back-ticks as punctuation. They are used as quotes around symbols or other code.
         .subtracting(CharacterSet(charactersIn: "-")) // Don't remove hyphens. They are used as a whitespace replacement.
     static let whitespaceAndDashes = CharacterSet.whitespaces
-        .union(CharacterSet(charactersIn: "-–—")) // hyphen, en dash, em dash
+        .union(CharacterSet(charactersIn: "-\u{2013}\u{2014}")) // hyphen, en dash, em dash
 }
 
 /// Creates a more readable version of a fragment by replacing characters that are not allowed in the fragment of a URL with hyphens.