docs: add installation prerequisites and quickstart guide to README

tests/oop_step0.rc

@@ -0,0 +1,11 @@
+class Empty {
+    int value = 42;
+}
+
+int main() {
+    printf("Step 0: No OOP, just testing class skipping\n");
+    int x = 5;
+    printf("x = %d\n", x);
+    printf("Success!\n");
+    return 0;
+}