add missing bits related to display note

* Re-adds `Display Note` to the alphabetical list
* Updates title of `Display Note` page
* Adds `Display Note` to the aardvark schema JSON file

Author: rmseifried

docs/ogm-aardvark.md

@@ -110,6 +110,7 @@ has_toc: false
 | [Date Issued](ogm-aardvark/date-issued)               | `dct_issued_s`         | Optional    |
 | [Date Range](ogm-aardvark/date-range)                 | `gbl_dateRange_drsim`  | Optional    |
 | [Description](ogm-aardvark/description)               | `dct_description_sm`   | Suggested |
+| [Display Note](ogm-aardvark/display-note)             | `gbl_displayNote_sm`   | Optional    |
 | [File Size](ogm-aardvark/file-size)                   | `gbl_fileSize_s`       | Optional    |
 | [Format](ogm-aardvark/format)                         | `dct_format_s`         | Conditional |
 | [Geometry](ogm-aardvark/geometry)                     | `locn_geometry`        | Suggested |

docs/ogm-aardvark/display-note.md

@@ -5,9 +5,9 @@ parent: OGM Aardvark
 nav_order: 4.5
 ---
 
-## Description
+## Display Note
 
-| Label                 | Description             |
+| Label                 | Display Note            |
 |:----------------------|:------------------------|
 | URI                   | `gbl_displayNote_sm`    |
 | Obligation            | Optional                |

schema/geoblacklight-schema-aardvark.json

@@ -24,6 +24,12 @@
         "type": "string"
       }
     },
+    "gbl_displayNote_sm": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      }
+    },
     "dct_creator_sm": {
       "type": "array",
       "items": {