Links in markdown are not parsed correctly

Here's a possible fix:

func addSpaceAfterLinks(_ content: String) -> String {
    let pattern = /https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&\/\/=]*)(?![\n\s])/

    let modifiedContent = content.replacing(pattern, maxReplacements: 10) { match in
        content[match.range] + " "
    }

    return modifiedContent
}

But the regex still needs fix. It cannot handle contents like

http://www.whxinan.net/dongman/mingzhentankenanwanshengjiedexinniang/2-1.html 这个网站有人在电影院拍的，勉强能看吧

https://www.wjx.cn/vm/hxjo6de.aspx# 
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DanXi-Dev / DanXi-swift

Links in markdown are not parsed correctly #221