[spec/type] Add example for derived types (#3904)

Add item for type sequences.

Author: ntrel

spec/type.dd

@@ -145,8 +145,23 @@ $(H2 $(LEGACY_LNAME2 Derived Data Types, derived-data-types, Derived Data Types)
     $(LI $(DDLINK spec/hash-map, Associative Array, Associative Arrays))
     $(LI $(RELATIVE_LINK2 functions, Function Types))
     $(LI $(RELATIVE_LINK2 delegates, Delegate Types))
+    $(LI $(DDSUBLINK spec/template, homogeneous_sequences, Type Sequences))
     )
 
+$(SPEC_RUNNABLE_EXAMPLE_COMPILE
+---
+int* p; // pointer
+int[2] sa; // static array
+int[] da; // dynamic array/slice
+
+int[string] aa; // associative array
+void function() fp; // function pointer
+
+import std.meta : AliasSeq;
+AliasSeq!(int, string) tsi; // type sequence instance
+---
+)
+
 $(H3 $(LNAME2 pointers, Pointers))
 
         $(P A pointer to type $(D T) has a value which is a reference (address) to another