title: How to import external javascript library into Bokeh generated html
body: <p>I would like to make use of a javascript library (specifically <a href="https://github.com/toji/gl-matrix/blob/master/dist/gl-matrix.js" rel="nofollow noreferrer">this one</a>) in my Bokeh javascript callback. How can I specify importing of this javascript library such that the library is accessible from Bokeh's js callback functions?</p>
  
  <p>The examples at:</p>
  
  <p><a href="https://docs.bokeh.org/en/latest/docs/user_guide/extensions.html" rel="nofollow noreferrer">https://docs.bokeh.org/en/latest/docs/user_guide/extensions.html</a> </p>
  
  <p>mainly talk about creating a custom Bokeh Model. I am not particularly interested in creating a new Model, just want to use the library functions in a callback to modify the data that is plotted.</p>