Used *.c extension and lower case dir name

diff --git a/examples/Graphics/Printing/BothScreenText/Makefile b/examples/graphics/printing/both-screen-text/Makefile
similarity index 100%
rename from examples/Graphics/Printing/BothScreenText/Makefile
rename to examples/graphics/printing/both-screen-text/Makefile

diff --git a/examples/Graphics/Printing/BothScreenText/source/main.cpp b/examples/graphics/printing/both-screen-text/source/main.c
similarity index 100%
rename from examples/Graphics/Printing/BothScreenText/source/main.cpp
rename to examples/graphics/printing/both-screen-text/source/main.c