Inserts n1 at the beginning of L1 (at index 0) and shifts the index of all other elements in the list up by 1

#prepends the value "hello" to the beginning of list01
<-list01 "hello" PrependToList

Sample list01:
0 - foo
1 - bar

Sample list01 after PrependToList command:
0 - hello
1 - foo
2 - bar