effective-go-til.md

1. Switch is more flexible than C's: https://golang.org/doc/effective_go.html#switch
2. Returns the address of a local variable is okay https://golang.org/doc/effective_go.html#composite_literals
3. Init function, not helpful to algorithm contests but good for day-to-day stuff https://golang.org/doc/effective_go.html#composite_literals
4. The address oprator can be inserted before variables automatically by compiler https://golang.org/doc/effective_go.html#pointers_vs_values