missing space in sentence

Former-commit-id: 3796ae2479
Former-commit-id: 3224a6b63f

node/src/documents/introduction/definitions.html

@@ -105,7 +105,7 @@ type   : 'UI Introduction'
 
   <h2 class="ui dividing header">UI Collections</h2>
 
-  <p>UI Collections are groups of heterogeneouspage elements which are usually found together. Carrying the chemistry metaphor, these can be thought of as molecules.</p>
+  <p>UI Collections are groups of heterogeneous page elements which are usually found together. Carrying the chemistry metaphor, these can be thought of as molecules.</p>
 
   <p>UI collections have a definition of elements that exist, or could exist inside of them. They do not usually require all elements to be found, but they describe a list of the "usual suspects". Unlike elements definitions, collections are not typically useful to define in plural.</p>