Add .gitattributes

Author: wsnyder

.gitattributes

@@ -0,0 +1,5 @@
+*.v linguist-language=SystemVerilog
+*.vh linguist-language=SystemVerilog
+*.sv linguist-language=SystemVerilog
+*.svh linguist-language=SystemVerilog
+nodist linguist-detectable=false

MANIFEST.SKIP

@@ -15,6 +15,7 @@
 \.def$
 \.dll$
 \.exp$
+\.gitattributes$
 \.tmp$
 \.vcs.*$
 \.pre\..*$