Add the sorted check, checking "difficulty-then-slug" (#3146)

Author: IsaacG

.github/workflows/sorted.yml

@@ -0,0 +1,16 @@
+name: Exercise order
+
+on:
+  pull_request:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  call-gha-workflow:
+    name: Check
+    uses: IsaacG/github-actions/.github/workflows/sorted.yml@main
+    with:
+      ordering: ".difficulty, .lowercase_name"

config.json

@@ -431,6 +431,17 @@
       }
     ],
     "practice": [
+      {
+        "slug": "hello-world",
+        "name": "Hello World",
+        "uuid": "19957346-dedf-441e-85ea-656cac0d96d8",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1,
+        "topics": [
+          "strings"
+        ]
+      },
       {
         "slug": "accumulate",
         "name": "Accumulate",
@@ -458,17 +469,6 @@
         "difficulty": 1,
         "status": "deprecated"
       },
-      {
-        "slug": "hello-world",
-        "name": "Hello World",
-        "uuid": "19957346-dedf-441e-85ea-656cac0d96d8",
-        "practices": [],
-        "prerequisites": [],
-        "difficulty": 1,
-        "topics": [
-          "strings"
-        ]
-      },
       {
         "slug": "hexadecimal",
         "name": "Hexadecimal",