rust impl simple grep

eg: cargo run 'hel' '*.txt'

reuslt:

file_name:./b.txt
1:5 fjeo hello fj
2:12 fejo11 3 hh helo
file_name:./a.txt
1:0 hello nn hel
1:9 hello nn hel
3:8 ojfefjeohel
6:0 hello ff```