Please check with me if you wish to make links to other content types. The server will also check the content of each file. If you declare the file to be of one type but the server determines it to be of another, the server wins. Using HTML only, you cannot normally set up a link to allow users to download a file. You can however, take advantage of the fact that some encoded file types are handled by helper applications that only decode the file and take no further action.
Prime examples are tar and gz files.
If you want your readers to download a file, first encode the file and then place a link to the encoded file in your web page. The outcome is not guaranteed though as web browsers can be set up differently by each visitor. In addition to using proper file name extensions please note that file names are case sensitive but stick to one case consistently, do not place spaces in file or directory names, restrict file names to alphanumerical characters, the dash, the underscore and the period and keep names short. Please follow these guidelines for file and directory names. Otherwise you will find that your links will not work with some browsers.