docs(vendor): add version.txt tracking files for imgui, llvm, raylib, and rlImGui

vendor/llvm/version.txt

@@ -0,0 +1,11 @@
+Name: LLVM / libclang
+Version: 19.1.0
+CIndexVersion: 0.64
+Target: x86_64-pc-windows-msvc
+Repository: https://github.com/llvm/llvm-project
+License: Apache-2.0 with LLVM Exception
+Binaries:
+  - vendor/llvm/lib/libclang.lib (x64 import library)
+  - build/libclang.dll (runtime shared library copied from LLVM 19.1.0)
+Headers:
+  - vendor/llvm/include/clang-c/ (libclang C indexing API)