Sort 'tag' results

Finding that I'm piping output through 'sort' often when searching by
tags so default to outputting notes in chronological order so that
sorting no longer relies on the path location but instead the note ID
(which will result in chronological order as IDs are a date
representation).

notebook/notebook.go

@@ -302,7 +302,7 @@ func (book *Notebook) MatchedTags(searchTags ...string) []matchedTag {
     return tagVerticesSlice
 }
 
-func (book *Notebook) TagIntersection(matchedTags []matchedTag) map[uint64]graph.Vertex {
+func (book *Notebook) TagIntersection(matchedTags []matchedTag) []graph.Vertex {
 	var intersection = make(map[uint64]graph.Vertex)
 	var mostConnectedVertex = matchedTags[0]
 VERTEX:
@@ -315,7 +315,20 @@ VERTEX:
 		intersection[vertexId] = book.Notes.Vertices[vertexId]
 	}
 
-    return intersection
+    var sortedVertices []uint64
+    for vertexId := range intersection {
+        sortedVertices = append(sortedVertices, vertexId)
+    }
+    sort.SliceStable(sortedVertices, func(i, j int) bool {
+        return sortedVertices[i] < sortedVertices[j]
+    })
+
+    var sortedIntersection []graph.Vertex
+    for _, vertexId := range sortedVertices {
+        sortedIntersection = append(sortedIntersection, intersection[vertexId])
+    }
+
+    return sortedIntersection
 }
 
 func (book *Notebook) addTag(tag string) uint64 {