Update README.md


```
>> require "ltsv"
=> true
>> value = {label1: "value1", label2: "value2"}
=> {:label1=>"value1", :label2=>"value2"}
>> dumped = LTSV.dump(value)
=> "label1:value1\tlabel2:value2"
>> open("tmp.ltsv","w"){|f| f.write(dumped) }
=> 27
>> LTSV.load("tmp.ltsv")
=> [{:label1=>"value1", :label2=>"value2"}]
>> LTSV.parse("tmp.ltsv")
=> [{:"tmp.ltsv"=>nil}]
```