feat: add some documentation

* README.md

Author: elsa

README.md

@@ -105,6 +105,14 @@ options is not needed. The `-ldd_trace_cpp` option is always needed.
 c++ -o my_app my_app.o -L/path/to/dd-trace-cpp/.install/lib -ldd_trace_cpp
 ```
 
+### Optional: Trace to Profile correlation
+In order to correlate traces to profiles generated by the full host profiler[[1](https://github.com/DataDog/opentelemetry-ebpf-profiler), [2](https://github.com/DataDog/dd-otel-host-profiler)],
+there are a couple of requirements for the build:
+
+[//]: # (TODO: add a link to the specification)
+- The app must be built on linux since the profiler leverages eBPF, a Linux kernel feature.
+- The compiler used for the build must support the `-mlts-dialect={gnu2/desc}` flag (GCC-11+ and Clang-19+).
+
 Test
 ----
 Pass `-DDD_TRACE_BUILD_TESTING=1` to `cmake` to include the unit tests in the build.