copy link to room button

[TheOrangeOne]

create a button that will go in the header bar that will copy the url to the room to the user's clipboard so that they can share it effortlessly.

we'll have to use a library here: https://github.com/zenorocha/clipboard.js/#usage see that link for how to use it.

to use this library in our javascript add:
<script src="https://unpkg.com/clipboard@2.0.0/dist/clipboard.min.js"></script>
to the top of room.html, where these are:

locus68/static/room.html

Lines 17 to 21 in 0991616

	<link rel="stylesheet" href="/static/css/pure-min.css"/>
	<script src="/static/js/vue.min.js" type="text/javascript"></script>
	<!--<script src="/static/js/vue.js" type="text/javascript"></script>-->
	<script src="/static/js/forge.min.js" type="text/javascript"></script>
	<script src="/static/js/reconnecting-websocket.min.js" type="text/javascript"></script>

for the icon for the button, we can use https://fontawesome.com/icons/clipboard?style=regular&from=io

all the button should do it copy the link of the current room to the clipboard

to get the link to the room use window.location.href