update github stuff

.gitattributes

@@ -5,3 +5,7 @@
 # Systemverilog files
 *.sv    text diff=systemverilog
 *.svh   text diff=systemverilog
+
+# C files
+*.c     text diff=c
+*.h     text diff=c

.gitignore

@@ -4,3 +4,4 @@
 # Folders
 gtkwave
 testbench
+.vscode