muk_web/muk_web_preview/static/description/index.html

<section class="oe_container">
    <div class="oe_row oe_spaced">
        <h2 class="oe_slogan">Preview Dialog</h2>
        <h3 class="oe_slogan">Preview your files directly in Odoo.</h3>
        <h4 class="oe_slogan" style="font-size: 23px;">MuK IT GmbH , www.mukit.at</h4>
         <div class="oe_demo oe_picture oe_screenshot">
            <img src="screenshot.png">
        </div>
    </div>
</section>

<section class="oe_container oe_dark" style="padding-top: 25px;">
	<div class="oe_row oe_spaced">
		<div class="oe_picture">
			<h3 class="oe_slogan">Overview</h3>
			<p class="oe_mt32">
				Adds a button to the FieldBinaryFile form widget to preview the file content directly in the browser.
				Currently the following file extensions are supported:
			</p>
			<p>
				<span style="color: green;"> &#9745; </span> Portable Document Format (.pdf) <br />
				<span style="color: green;"> &#9745; </span> Open Document (.odt, .odp, .ods, .otp) <br /> 
			</p>
		</div>
	</div>
</section>