all items need update methods

[bmarwell]

Todo:

Edit the file
https://github.com/bmhm/alttpr-vue-twitch-chat-tracker/blob/master/src/js/ItemUpdates.js

For every item, add a (for now static) method with it's item name.
If it's a two-state-item (on/off), call trackerItem.nextState().
Otherwise call setState(num), where 0=off, 1=1st image, 2=2nd image etc.

Edit the file https://github.com/bmhm/alttpr-vue-twitch-chat-tracker/blob/master/src/views/Tracker.vue
Create a update parameter for each item and add the reference as already done in bow and arrows and boomerang items.

That's it!