DEVELOPERS: add myself to more packages

Signed-off-by: Michael Nosthoff <buildroot@heine.tech>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

DEVELOPERS

@@ -2105,12 +2105,16 @@ F:	package/gnuplot/
 F:	package/sdl2/
 
 N:	Michael Nosthoff <buildroot@heine.tech>
+F:	package/boost/
+F:	package/fmt/
 F:	package/grpc/
 F:	package/gtest/
+F:	package/json-for-modern-cpp/
 F:	package/libabseil-cpp/
 F:	package/networkd-dispatcher/
 F:	package/protobuf/
 F:	package/re2/
+F:	package/spdlog/
 
 N:	Michael Rommel <rommel@layer-7.net>
 F:	package/knock/