add release notes blurb about plugin loading
add release notes blurb about plugin loading

nathandunn/jbrowse,GMOD/jbrowse,GMOD/jbrowse,nathandunn/jbrowse,GMOD/jbrowse,GMOD/jbrowse,nathandunn/jbrowse,nathandunn/jbrowse,GMOD/jbrowse,nathandunn/jbrowse