diff --git a/source/javascripts/lib/_lunr.js b/source/javascripts/lib/_lunr.js
index c353765..6aa370f 100644
--- a/source/javascripts/lib/_lunr.js
+++ b/source/javascripts/lib/_lunr.js
@@ -1,6 +1,6 @@
 /**
- * lunr - http://lunrjs.com - A bit like Solr, but much smaller and not as bright - 2.3.8
- * Copyright (C) 2019 Oliver Nightingale
+ * lunr - http://lunrjs.com - A bit like Solr, but much smaller and not as bright - 2.3.9
+ * Copyright (C) 2020 Oliver Nightingale
  * @license MIT
  */
 
@@ -54,10 +54,10 @@ var lunr = function (config) {
   return builder.build()
 }
 
-lunr.version = "2.3.8"
+lunr.version = "2.3.9"
 /*!
  * lunr.utils
- * Copyright (C) 2019 Oliver Nightingale
+ * Copyright (C) 2020 Oliver Nightingale
  */
 
 /**
@@ -177,7 +177,7 @@ lunr.FieldRef.prototype.toString = function () {
 }
 /*!
  * lunr.Set
- * Copyright (C) 2019 Oliver Nightingale
+ * Copyright (C) 2020 Oliver Nightingale
  */
 
 /**
@@ -211,8 +211,8 @@ lunr.Set.complete = {
     return other
   },
 
-  union: function (other) {
-    return other
+  union: function () {
+    return this
   },
 
   contains: function () {
@@ -389,7 +389,7 @@ lunr.Token.prototype.clone = function (fn) {
 }
 /*!
  * lunr.tokenizer
- * Copyright (C) 2019 Oliver Nightingale
+ * Copyright (C) 2020 Oliver Nightingale
  */
 
 /**
@@ -465,7 +465,7 @@ lunr.tokenizer = function (obj, metadata) {
 lunr.tokenizer.separator = /[\s\-]+/
 /*!
  * lunr.Pipeline
- * Copyright (C) 2019 Oliver Nightingale
+ * Copyright (C) 2020 Oliver Nightingale
  */
 
 /**
@@ -732,7 +732,7 @@ lunr.Pipeline.prototype.toJSON = function () {
 }
 /*!
  * lunr.Vector
- * Copyright (C) 2019 Oliver Nightingale
+ * Copyright (C) 2020 Oliver Nightingale
  */
 
 /**
@@ -929,7 +929,7 @@ lunr.Vector.prototype.toJSON = function () {
 /* eslint-disable */
 /*!
  * lunr.stemmer
- * Copyright (C) 2019 Oliver Nightingale
+ * Copyright (C) 2020 Oliver Nightingale
  * Includes code from - http://tartarus.org/~martin/PorterStemmer/js.txt
  */
 
@@ -1151,7 +1151,7 @@ lunr.stemmer = (function(){
 lunr.Pipeline.registerFunction(lunr.stemmer, 'stemmer')
 /*!
  * lunr.stopWordFilter
- * Copyright (C) 2019 Oliver Nightingale
+ * Copyright (C) 2020 Oliver Nightingale
  */
 
 /**
@@ -1316,7 +1316,7 @@ lunr.stopWordFilter = lunr.generateStopWordFilter([
 lunr.Pipeline.registerFunction(lunr.stopWordFilter, 'stopWordFilter')
 /*!
  * lunr.trimmer
- * Copyright (C) 2019 Oliver Nightingale
+ * Copyright (C) 2020 Oliver Nightingale
  */
 
 /**
@@ -1343,7 +1343,7 @@ lunr.trimmer = function (token) {
 lunr.Pipeline.registerFunction(lunr.trimmer, 'trimmer')
 /*!
  * lunr.TokenSet
- * Copyright (C) 2019 Oliver Nightingale
+ * Copyright (C) 2020 Oliver Nightingale
  */
 
 /**
@@ -1827,7 +1827,7 @@ lunr.TokenSet.Builder.prototype.minimize = function (downTo) {
 }
 /*!
  * lunr.Index
- * Copyright (C) 2019 Oliver Nightingale
+ * Copyright (C) 2020 Oliver Nightingale
  */
 
 /**
@@ -1994,7 +1994,7 @@ lunr.Index.prototype.query = function (fn) {
      */
     var clause = query.clauses[i],
         terms = null,
-        clauseMatches = lunr.Set.complete
+        clauseMatches = lunr.Set.empty
 
     if (clause.usePipeline) {
       terms = this.pipeline.runString(clause.term, {
@@ -2319,7 +2319,7 @@ lunr.Index.load = function (serializedIndex) {
 }
 /*!
  * lunr.Builder
- * Copyright (C) 2019 Oliver Nightingale
+ * Copyright (C) 2020 Oliver Nightingale
  */
 
 /**