Update docs

Author: Moe-hacker

README.md

@@ -8,6 +8,15 @@ cprintf("{}\n", F(i,"06")); // Equal to printf("%06d\n", i);
 ```
 And, now we have `csprintf()`, it supports T() F() but don't support color.      
 On linux, cprintf() and cfprintf() will auto disable color when output to a pipe.            
+# Warning:
+cprintf is not more secure than printf(), and, please always use unchangable format string and make sure there's not extra {}!      
+For example:
+```C
+printf("%s%s%s%s","xxxxx"); // Boom!
+cprintf("{}{}{}{}","xxxxx"); // Also boom!!!!!!
+printf("%s","xxxxx"); // Good!
+cprintf("{}","xxxxxx"); // Also good :)
+```
 # Let's make a colorful world!
 # What's this?
 We often use ASCII color like `\033[0m` when developing. But it's hard to remember them.          

test.c

@@ -105,4 +105,5 @@ int main(void)
 
 	int i = 0;
 	cprintf("{}\n", T(i));
+	cprintf("{}\n", "{}{}{}{}");
 }