Deleting redundant submodules

.gitmodules

@@ -1,45 +1,6 @@
-[submodule "external/glm"]
-	path = external/glm
-	url = https://github.com/g-truc/glm.git
-[submodule "external/glfw"]
-	path = external/glfw
-	url = https://github.com/glfw/glfw.git
-[submodule "external/json"]
-	path = external/json
-	url = https://github.com/nlohmann/json.git
-[submodule "external/assimp"]
-	path = external/assimp
-	url = https://github.com/assimp/assimp.git
-[submodule "external/stb"]
-	path = external/stb
-	url = https://github.com/nothings/stb
-[submodule "external/slang"]
-	path = external/slang
-	url = https://github.com/shader-slang/slang.git
-[submodule "external/ktx"]
-	path = external/ktx
-	url = https://github.com/KhronosGroup/KTX-Software
-[submodule "external/ttf-parser"]
-	path = external/ttf-parser
-	url = git@github.com:kv01/ttf-parser.git
-[submodule "external/freetype"]
-	path = external/freetype
-	url = https://gitlab.freedesktop.org/freetype/freetype.git
-[submodule "external/entt"]
-	path = external/entt
-	url = git@github.com:skypjack/entt.git
-[submodule "external/thread-pool"]
-	path = external/thread-pool
-	url = https://github.com/DeveloperPaul123/thread-pool.git
-[submodule "external/zlib"]
-	path = external/zlib
-	url = https://github.com/madler/zlib.git
 [submodule "external/CRCpp"]
 	path = external/CRCpp
 	url = https://github.com/d-bahr/CRCpp.git
-[submodule "external/odeint"]
-	path = external/odeint
-	url = https://github.com/headmyshoulder/odeint-v2.git
 [submodule "external/vcpkg"]
 	path = external/vcpkg
-	url = https://github.com/Microsoft/vcpkg.git
+	url = https://github.com/Microsoft/vcpkg.git