added type as prop so we can use Number as type for the input.#14

Hi there, I see that there is an opened issue https://github.com/iamstevendao/vue-suggestion/issues/13, basically it requires to change the type to "number" instead of "search" so I make the changes that are necessary to be able to change the default input type "search" value as any type like "number" by assign it a property with the same name. I would appreciate that you evaluate this pull request. I followed the style and conventions and I already modified the Readme file so users can know about the little feature. I put an example of animal name with a number as name ("123456") so I can test it , I attach the image so you can see how does it look like. ## vue example ```html <vue-suggestion v-model="item" type="number" :items="items" :setLabel="setLabel" :itemTemplate="itemTemplate" maxLen="20" @changed="inputChange" ></vue-suggestion> ``` ## image: This is the result.  Let me know if this is right. Thanks