📝 optimize code format

std/string.nas

@@ -1,10 +1,10 @@
 # string.nas
 # ValKmjolnir 2022/10/5
 
-var join=func(sep, vec){
+var join = func(sep, vec){
     var len = size(vec);
     var res = "";
-    for(var i = 0; i<len; i+=1) {
+    for(var i = 0; i<len; i += 1) {
         res ~= vec[i];
         res ~= (i==len-1? "":sep);
     }