Rename struct String to struct dstr

dstr/include/dstr.h

@@ -3,7 +3,7 @@
 
 #include "aliases.h"
 
-typedef struct String String;
+typedef struct dstr String;
 
 String *dstr_with_capacity(u64 capacity);
 String *dstr_from_string(const char *str);

dstr/src/dstr.c

@@ -8,7 +8,7 @@
 // constantly reallocate
 #define CAPACITY_SCALAR 8
 
-struct String {
+struct dstr {
   u64 capacity;
   u64 size;
   char buf[];