Fixed path separators in diagram link URL's in Windows

src/util/util.cc

@@ -303,4 +303,20 @@ std::size_t hash_seed(std::size_t seed)
     return kSeedStart + (seed << kSeedShiftFirst) + (seed >> kSeedShiftSecond);
 }
 
+std::string path_to_url(const std::filesystem::path& p) {
+    std::vector<std::string> path_tokens;
+    auto it = p.begin();
+    if(p.has_root_directory())
+        it++;
+
+    for(; it != p.end(); it++)
+        path_tokens.push_back(it->string());
+
+    if(p.has_root_directory())
+        return fmt::format("/{}", fmt::join(path_tokens, "/"));
+    else
+        return fmt::format("{}", fmt::join(path_tokens, "/"));
+
+}
+
 } // namespace clanguml::util