Change note creation script uses EDITOR environment variable

Changes the script for creating change notes to read the EDITOR environment variable, and use the editor specified therein. This makes the script more convenient when used from a terminal. The VSCode task is updated to the set EDITOR to `code -r` which preserves the current behavior.

.vscode/tasks.json

@@ -50,6 +50,11 @@
                 "${input:name}",
                 "${input:categoryQuery}"
             ],
+            "options": {
+                "env": {
+                    "EDITOR": "code -r",
+                }
+            },
             "presentation": {
                 "reveal": "never",
                 "close": true
@@ -67,6 +72,11 @@
                 "${input:name}",
                 "${input:categoryLibrary}"
             ],
+            "options": {
+                "env": {
+                    "EDITOR": "code -r"
+                }
+            },
             "presentation": {
                 "reveal": "never",
                 "close": true