WKWebView Loading is Too Slow - ios

Question

I am using MarkDonwView Library : https://github.com/keitaoouchi/MarkdownView
Which is converting MD String to show as a webview. Rendering is taking too long as it loads everything and then shows the view. Is it possible to make image loading async while showing text body ASAP so it will not look like its too slow ?
This is how it is loading the html file.
if bundle.bundleIdentifier?.hasPrefix("org.cocoapods") == true {
htmlURL = bundle.url(forResource: "index",
withExtension: "html",
subdirectory: "MarkdownView.bundle")
} else {
htmlURL = bundle.url(forResource: "index",
withExtension: "html")
}
if let url = htmlURL {
let templateRequest = URLRequest.init(url: url, cachePolicy: .returnCacheDataElseLoad, timeoutInterval: 60) //URLRequest(url: url)
let escapedMarkdown = self.escape(markdown: markdown) ?? ""
let imageOption = enableImage ? "true" : "false"
let script = "window.showMarkdown('\(escapedMarkdown)', \(imageOption));"
let userScript = WKUserScript(source: script, injectionTime: .atDocumentEnd, forMainFrameOnly: true)
let controller = WKUserContentController()
controller.addUserScript(userScript)
let configuration = WKWebViewConfiguration()
configuration.userContentController = controller
let wv = WKWebView(frame: self.bounds, configuration: configuration)
wv.scrollView.isScrollEnabled = self.isScrollEnabled
wv.translatesAutoresizingMaskIntoConstraints = false
wv.navigationDelegate = self
addSubview(wv)
wv.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
wv.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
wv.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true
wv.trailingAnchor.constraint(equalTo: self.trailingAnchor).isActive = true
wv.backgroundColor = self.backgroundColor
self.webView = wv
wv.load(templateRequest)
} else {
// TODO: raise error
}