rename runtime to std and update example

example.lisp

@@ -1 +1,2 @@
-(print_str "guh")
+(print_str "hello world")
+(print_num (add 5 (divide 100 5)))

src/codegen.c

@@ -3,7 +3,7 @@
 
 const char* codegen(ASTNode* node) {
     if(node->type == AST_PROGRAM) {
-        sl_string code = sl_string("#include <runtime.h>\n\nint main() {\n");
+        sl_string code = sl_string("#include <std.h>\n\nint main() {\n");
         for(sl_vec_it(n, node->body)) {
             sl_append_c_str(&code, codegen(*n));
             sl_append_c_str(&code, ";\n");

src/main.c

@@ -32,8 +32,8 @@ int main(int argc, char* argv[]) {
     TCCState* state = tcc_new();
     assert(tcc_set_output_type(state, TCC_OUTPUT_EXE)   == 0);
     tcc_set_lib_path(state, "lib/tcc");
-    assert(tcc_add_include_path(state, "runtime")       == 0);
-    assert(tcc_add_file(state, "runtime/runtime.c")     == 0);
+    assert(tcc_add_include_path(state, "std")       == 0);
+    assert(tcc_add_file(state, "std/std.c")     == 0);
     assert(tcc_compile_string(state, code)              == 0);
     assert(tcc_output_file(state, argv[2])              == 0);
 

std/std.c

@@ -1,4 +1,4 @@
-#include "runtime.h"
+#include "std.h"
 #include <stdio.h>
 
 int add(int a, int b) {