fuzzers: Silence doxygen warnings

There's a lot of missing doxygen in the cli.h file. Add a TODO and disable it for now.

Change-Id: Iebd2bf76be73ad0233e4a7dbd893fc3603efa172
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/56061
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@chromium.org>
Auto-Submit: Ben Clayton <bclayton@google.com>
Reviewed-by: Vasyl Teliman <vasniktel@gmail.com>
Reviewed-by: Ben Clayton <bclayton@google.com>

fuzzers/tint_spirv_tools_fuzzer/cli.h

@@ -20,6 +20,9 @@
 
 #include "source/fuzz/fuzzer.h"
 
+// TODO(vasniktel): Add doxygen comments.
+//! @cond Doxygen_Suppress
+
 namespace tint {
 namespace fuzzers {
 namespace spvtools_fuzzer {
@@ -121,4 +124,6 @@ MutatorDebuggerCliParams ParseMutatorDebuggerCliParams(int argc,
 }  // namespace fuzzers
 }  // namespace tint
 
+//! @endcond
+
 #endif  // FUZZERS_TINT_SPIRV_TOOLS_FUZZER_CLI_H_