THRIFT-5855: Add c_glib fuzzers

Add fuzzers for c_glib support, to improve the reliability/robustness of the implementation
diff --git a/FUZZING.md b/FUZZING.md
index f0f0324..b3e0c15 100644
--- a/FUZZING.md
+++ b/FUZZING.md
@@ -16,10 +16,10 @@
 We currently maintain fuzzers for the following languages:
 
 - Go (needs improvement)
+- c_glib (partially supported, needs round-trip support)
 
 We are working on adding fuzzers for the following languages:
 
-- c_glib
 - C++
 - Rust  
 - Swift