Add cvars.c source with cv_bhop cvar

src/cvars.c

@@ -0,0 +1,12 @@
+
+#include "include/cvars.h"
+#include "include/sdk.h"
+#include "include/globals.h"
+
+DECL_CVAR(bhop);
+
+bool cvars_init(void) {
+    cv_bhop = REGISTER_CVAR("bhop", "1");
+
+    return true;
+}