chore(learn): Renamed all project-based curriculum project step filenames to use 3-digit format of part-ddd.md (#39463)

* fix: renamed basic html cat photo app steps

* fix: renamed css-variables project steps

* fix: renamed d3-dashboard filenames

* fix: renamed rpg-game filenames

* fix: renamed functional-progamming-spreadsheet filenames

* fix: renamed calorie-counter project filenames

curriculum/challenges/_meta/basic-javascript-rpg-game/meta.json

@@ -11,39 +11,39 @@
   "challengeOrder": [
     [
       "5d5a813321b9e3db6c106a46",
-      "Part 01"
+      "Part 1"
     ],
     [
       "5d5a8dd907f328a948d398ce",
-      "Part 02"
+      "Part 2"
     ],
     [
       "5d5a8f1c07f328a948d398cf",
-      "Part 03"
+      "Part 3"
     ],
     [
       "5d5a903507f328a948d398d0",
-      "Part 04"
+      "Part 4"
     ],
     [
       "5d5aaa5807f328a948d398d1",
-      "Part 05"
+      "Part 5"
     ],
     [
       "5d5aab5d07f328a948d398d2",
-      "Part 06"
+      "Part 6"
     ],
     [
       "5d5aac9c07f328a948d398d3",
-      "Part 07"
+      "Part 7"
     ],
     [
       "5d5aad2307f328a948d398d4",
-      "Part 08"
+      "Part 8"
     ],
     [
       "5d5aae1207f328a948d398d5",
-      "Part 09"
+      "Part 9"
     ],
     [
       "5d5ab57f07f328a948d398d6",
@@ -121,10 +121,6 @@
       "5d6653d5e0696bdec46938da",
       "Part 28"
     ],
-    [
-      "5d665767e0696bdec46938db",
-      "Part 28"
-    ],
     [
       "5d665983e0696bdec46938dc",
       "Part 29"