fix: convert cf-kv and excalidraw-libraries from submodules to regular files

- Remove stale cloudflare-worker submodule entry from .gitmodules
- Remove .git dirs from cf-kv and excalidraw-libraries so Git tracks them as regular files
- Fixes 'No url found for submodule path cf-kv' CI error

excalidraw-libraries/stats/2021-05/2021-05-13.json

@@ -0,0 +1,41 @@
+{
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+  "dbssticky-data-viz": 24,
+  "drwnio-drwnio": 48,
+  "drwnio-storytelling": 14,
+  "dwelle-hearts": 1,
+  "ei-au-computers": 60,
+  "excacomp-mobile-kit": 4,
+  "excacomp-web-kit": 14,
+  "franky47-apple-devices-frames": 1,
+  "g-script-android": 4,
+  "g-script-charts": 13,
+  "g-script-forms": 36,
+  "g-script-medias": 5,
+  "h7y-dropdowns": 8,
+  "husainkhambaty-aws-simple-icons": 54,
+  "inwardmovement-information-architecture": 35,
+  "jakubpawlina-graphs": 5,
+  "jhoughes-veeam": 10,
+  "kaligule-robots": 12,
+  "lipis-polygons": 6,
+  "lipis-stars": 3,
+  "madhusuthanan-b-front-end-tech-and-tools": 42,
+  "madhusuthanan-b-html-css-js-icons": 3,
+  "maeddes-technology-logos": 26,
+  "marcottebear-raspberrypi-zero": 2,
+  "michelcaradec-cloud-design-patterns": 70,
+  "mikhailredis-redis-grafana": 10,
+  "morgemoensch-gadgets": 8,
+  "newbyca-cryptocurrencies": 2,
+  "ocapraro-bubbles": 16,
+  "pclainchard-it-logos": 13,
+  "revolunet-raspberrypi3": 1,
+  "rkjc-schematic-symbols": 5,
+  "shinkim-presentation-templates": 3,
+  "simalexan-wardley-maps-symbols": 5,
+  "slobodan-aws-serverless": 23,
+  "spfr-lo-fi-wireframing-kit": 22,
+  "youritjang-software-architecture": 105,
+  "youritjang-stick-figures": 47
+}