Add glibc compatibility note for Linux builds

Author: wu-vincent

README.md

@@ -63,6 +63,13 @@ CC=clang-18 CXX=clang++-18 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cmake --build build
 ```
 
+### A note on glibc (Linux)
+
+Plugins built on Linux are linked against glibc and can only run on servers with the same or
+newer glibc version. A plugin built on Ubuntu 24.04 will not load on a server running
+Ubuntu 22.04. To maximize compatibility, build on an older OS. GitHub Actions runners
+(Ubuntu 22.04) are a good default for this reason.
+
 ## Project Structure
 
 ```