Example for vspan and hspan (#4062)

* Example for vspan and hspan

* Format

* First time contributor

.zenodo.json

@@ -702,6 +702,10 @@
             "affiliation": "Alogus Research Corporation",
             "name": "Lee Phillips",
             "type": "Other"
+        },
+        {
+            "name": "Tom Gillam",
+            "type": "Other"
         }
     ],
     "upload_type": "software"

src/examples.jl

@@ -1264,6 +1264,19 @@ const _examples = PlotExample[
             ),
         ],
     ),
+    PlotExample( # 57
+        "Vertical and horizonal spans",
+        """
+        `vspan` and `hspan` can be used to shade horizontal and vertical ranges.
+        """,
+        [:(
+            begin
+                hspan([1, 2, 3, 4]; label = "hspan", legend = :topleft)
+                vspan!([2, 3]; alpha = 0.5, label = "vspan")
+                plot!([0, 2, 3, 5], [-1, 3, 2, 6]; c = :black, lw = 2, label = "line")
+            end
+        )],
+    ),
 ]
 
 # Some constants for PlotDocs and PlotReferenceImages